Apparatus and method for processing a substrate

BACKGROUND OF THE INVENTION

P-0001[0001] 1. Field of the Invention

P-0002[0002] The present invention relates to an apparatus and method for processing a substrate for use in the production of a semiconductor device (the apparatus for processing a substrate will be hereinafter occasionally referred to as “substrate-processing apparatus” and the method for processing a substrate will be hereinafter occasionally referred to as “substrate-processing method” for simplification purpose). More particularly, the present invention relates an improvement in the substrate-processing apparatus and substrate-processing method in which a substrate for a semiconductor device is wound in a roll form together with an interleaf before or after said substrate is treated. The substrate-processing apparatus includes a chemical vapor deposition (CVD) apparatus including a plasma CVD apparatus and the substrate-processing method includes a chemical vapor deposition (CVD) method including a plasma CVD method.

P-0003[0003] The present invention also relates an apparatus and process for producing a photovoltaic element by way of CVD including plasma CVD.

P-0004[0004] 2. Related Background Art

P-0005[0005] In recent years, various researches and developments have been conducted aiming at realization of sunlight power generation by means of a solar cell. In order to establish a definite situation for the sunlight power generation to meet the demand of electric power supply, it is required that solar cells having a sufficiently high photoelectric conversion efficiency and excelling in reliability are capable of being stably mass-produced and being always provided at a reasonable cost.

P-0006[0006] As such solar cell, public attention has been focused on an amorphous silicon (a-Si) solar cell (hereinafter referred to as “a-Si solar cell”), because the a-Si solar cell can be easily mass-produced at a reduced production cost and it can be stably provided at a reasonable cost, in comparison with a solar cell produced using a crystalline series silicon material or the like.

P-0007[0007] The reason for this is that the a-Si solar cell can be produced by using a raw material gas such as silane gas or the like which can be readily acquired at a reasonable cost and subjecting the raw material gas to glow discharge decomposition to form a functional deposited film such as a semiconductor film (or a semiconductor layer) or the like on a relatively inexpensive belt-like substrate (a substrate web) such as a metallic sheet or a resin sheet. And there have been proposed various film-forming method and apparatus for the production of an a-Si solar cell.

P-0008[0008] Incidentally, as such film-forming apparatus in order to form a functional deposited film as a semiconductor layer which is used in the production of a semiconductor device such as a solar cell, for instance, U.S. Pat. No. 4,400,409 (hereinafter referred to as document 1) discloses a plasma CVD continuous film-forming apparatus of a roll-to-roll system which can continuously form a functional deposited film as a semiconductor layer at a significant productivity. Document 1 describes that according to the plasma CVD continuous film-forming apparatus disclosed therein, it is possible to continuously form an element having a semiconductor junction by providing a long web member as a substrate on which a deposited film is to be formed and continuously moving in the longitudinal direction while passing said web member through a plurality of glow discharge regions to form a desired functional deposited film on said web member in each glow discharge region.

P-0009[0009] Besides, U.S. Pat. No. 4,485,125 (hereinafter referred to as document 2) discloses a method of continuously forming a deposited film on a long web member using a plasma CVD film-forming apparatus of a roll-to-roll system in which a substrate protective sheet is used such that said substrate protective sheet is laid on the surface of a deposited film formed on the web member. Document 2 describes that according to the film-forming method described therein, it possible to continuously form a high quality deposited film on a long web member at good reproducibility and at a high yield throughout from the beginning to the termination of the web member.

P-0010[0010] In addition, Japanese Unexamined Patent Publication No. 82652/1997 (hereinafter referred to as document 3) discloses a method of forming a semiconductor film on a web substrate, including a step (a) of delivering a web substrate from a pay-out bobbin prior to forming a desired deposited film on said web substrate and a step (b) taking up said web substrate having said desired film formed thereon on a take-up bobbin through a steering roller while winding the web substrate winding on the take-up bobbin, wherein in said step (a) and said step (b), an interleaf comprising a resin, a chemical fiber or a glass wool is interposed between the web substrate and the steering roller in order to prevent occurrence of physical contact between the web substrate and the steering roller. Document 3 describes that according to the method described therein, shapes based on dusts or the like present on the back side of the web substrate are prevented from transferring onto the surface of the film formed on the web substrate and because of this, the surface of the film formed on the web substrate is prevented from being provided with irregularities.

P-0011[0011] However, the film-forming method described in document has such subjects as will be described below, which are required to improve.

P-0012[0012] That is, for instance, in the case where the formation of a deposited film on a web substrate in accordance with the roll-to-roll film-forming manner is continuously conducted over a long period of time, in the step wherein the web substrate wound in a roll form on the bobbin together with the interleaf interposed in the roll form to cover the film-forming face of the web substrate is delivered from the bobbin and moved in the longitudinal direction for film formation while the interleaf being separately delivered and wound on the bobbin for the interleaf, when strong adhesion is present between the web substrate and the interleaf due to adhesion or electrostatic absorption of the interleaf, there is a fear such that the interleaf is pulled in the steering roller whereby the interleaf is sandwiched between the web substrate and the steering roller, where the interleaf is broken or the interleaf is in a state that the interleaf is mounted on the back face of the web substrate and it is moved into a first film-forming chamber adjacent to the substrate-delivering chamber together with the web substrate while maintaining said state.

P-0013[0013] Further, in the case where the rotation performance of a bobbin shaft for winding the interleaf fails due to aging of bearings for the bobbin shaft because of continuous repetition of the film formation over a long period of time and the winding speed of the interleaf becomes slower than the peeling speed of the interleaf from the web substrate, there is a fear such that the interleaf is gradually loosed and eventually, the interleaf is moved into a first film-forming chamber adjacent to the substrate-delivering chamber together with the web substrate while the interleaf being mounted on the back face of the web substrate.

P-0014[0014] When the interleaf is not normally wound, there is -a tendency of causing problems such that abnormality is entailed for the transportation of the web substrate, and when the interleaf is taken into the first film-forming chamber as above described, depending upon the kind of the constituent of the interleaf, the interleaf is evaporated to deposit on the inner wall face or the like of the film-forming chamber or it is melted or burned in a worst case due to heat from the heater of the film-forming chamber, where the film-forming apparatus is greatly damaged.

P-0015[0015] Separately in the case where the web substrate having a plurality of deposited films sequentially formed thereon is wound on the bobbin, when the web substrate is wound on the bobbin together with a new interleaf while laying the interleaf on the film-forming surface of the web substrate so as to cover the film-forming surface and wherein the rotation performance of the bobbin shaft for delivering the interleaf fails and the speed for the interleaf to be delivered becomes faster than that for the web substrate to be wound on the bobbin, there is such a fear as will be described in the following. That is, the interleaf is gradually loosed and eventually, the interleaf is pulled in the steering roller in a state that the interleaf is mounted on the back face of the web substrate, where the interleaf is broken.

P-0016[0016] Without being noticed to the fact that the interleaf is broken during the film formation, when the film formation is continued, there is a tendency in that no interleaf is laid on the film-formed face of the web substrate which is wound after the time when the interleaf is broken. This situation is liable to entail a remarkable decrease in the yield of a film product and also in the characteristics thereof.

P-0017[0017] The occurrence of such problems as above described is limited only in the case of forming a deposited film on a web substrate by way of the roll-to-roll film-forming process. Similar problems are liable to occur also in the case of other substrate-processing apparatus in which a web substrate is treated by way of roll-to-roll manner. These substrate-processing apparatus include film-forming apparatus by means of sputtering, vapor deposition, CVD apparatus, plating, or coating, etching apparatus, and washing apparatus.

SUMMARY OF THE INVENTION

P-0018[0018] An principal object of the present invention is to eliminate the foregoing problems in the prior art and to provide an improved substrate-processing apparatus and method in which the foregoing troubles due to transport abnormality of the interleaf during the processing of a substrate (that is, the film formation on a substrate) which are found in the prior art are desirably eliminated.

P-0019[0019] Another object of the present invention is to provide a roll-to-roll film-forming apparatus and method which enable to efficiently form a high quality functional deposited film having satisfactory characteristics at an improved yield.

P-0020[0020] A further object of the present invention is to provide a roll-to-roll film-forming apparatus and method which enable to efficiently form a photovoltaic element including a solar cell having satisfactory characteristics.

P-0021[0021] A further object of the present invention is to provide a roll-to-roll substrate-processing apparatus comprising a substrate delivery chamber having a substrate delivery means having a web substrate (that is, a belt-like shaped long substrate) and an interleaf alternately wound and an interleaf takeup means which are provided therein, a substrate processing chamber (of a single- or multi-chambered system), and a substrate takeup chamber having a substrate takeup means and an interleaf delivery means having an interleaf wound thereon which are provided therein, wherein said substrate web and said interleaf are continuously delivered from said substrate delivery means where said interleaf delivered is continuously wound on said interleaf takeup means and said web substrate delivered is continuously transported into a substrate-processing chamber through a steering roller where said web substrate is subjected to desired processing, the web substrate processed in the substrate-processing chamber is continuously transported into said substrate takeup chamber where the web substrate is wound through a steering roller on said substrate takeup means together with an interleaf delivered from said interleaf delivery means such that the web substrate and the interleaf are alternately wound on the substrate takeup means, wherein said substrate-processing apparatus is provided with a mechanism to detect transport abnormality of the interleaf in the substrate delivery chamber or/and the substrate takeup chamber whereby preventing the interleaf from suffering adhesion to the web substrate and also preventing the interleaf from being taken into the substrate processing chamber together with the web substrate.

P-0022[0022] The term “adhesion” in the present invention indicates a state in that the interleaf and the substrate are contacted with each other. The present invention is aimed at detecting and preventing such contact (adhesion). Specifically, the present invention is aimed at preventing the interleaf from being transported in a state of being contacted (adhered) with the substrate.

P-0023[0023] According to the substrate-processing apparatus of the present invention, it is possible that a web substrate is continuously transported from the substrate delivery chamber into the substrate processing chamber while preventing the web substrate from being contacted with an interleaf which is delivered together with the web substrate where desired processing such as film formation is efficiently performed on the web substrate which is moving, and the substrate web thus processed in the substrate processing chamber is successively transported into the substrate takeup chamber where the web substrate is wound on the substrate takeup means while the processed surface of the web substrate being covered by an interleaf which is separately delivered without being contacted with the web substrate. Thus, there can be effectively obtained a rolled product comprising a web substrate having a processed surface (or having a deposited film formed thereon) and an interleaf which are alternately wound such that the processed surface (or the deposited film-bearing surface) of the web substrate is covered by the interleaf. This situation enables to efficiently and continuously form not only a high quality functional deposited film having satisfactory characteristics but also a high quality photovoltaic element (solar cell) having satisfactory characteristics on a web substrate at an improved yield.

P-0024[0024] The present invention also makes it an object to provide a substrate-processing method using the above substrate-processing apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

P-0025[0025]FIG. 1 is a schematic diagram illustrating an inside constitution of an example of a substrate takeup chamber as a part of a substrate-processing apparatus according to the present invention.

P-0026[0026]FIG. 2 is a schematic diagram illustrating an inside constitution of an example of a substrate delivery chamber as a part of a substrate-processing apparatus according to the present invention.

P-0027[0027]FIG. 3 is a schematic view illustrating an example of a rotation system of an interleaf bobbin used in a substrate-processing apparatus according to the present invention.

P-0028[0028]FIG. 4 is a schematic principle view for explaining a mechanism of detecting rotation abnormality of an interleaf bobbin, which is used in a substrate-processing apparatus according to the present invention.

P-0029[0029]FIG. 5 is a schematic diagram illustrating a roll-to-roll type DC magnetron sputtering apparatus as an example of a substrate-processing apparatus according to the present invention.

P-0030[0030]FIG. 6 is a schematic cross-sectional view illustrating an example of an amorphous silicon solar cell (photovoltaic element) produced in the present invention.

P-0031[0031]FIG. 7 is a schematic diagram illustrating a roll-to-roll type plasma CVD apparatus as an example of a substrate-processing apparatus according to the present invention.

DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

P-0032[0032] The present invention eliminates the foregoing problems found in the prior art and attain the above described objects.

P-0033[0033] As previously described, the present invention typically provides a substrate-processing apparatus comprising a substrate delivery chamber having a substrate delivery means having a web substrate (that is, a belt-like shaped long substrate) and an interleaf alternately wound and an interleaf takeup means which are provided therein, a substrate processing chamber (of a single- or multi-chambered system), and a substrate takeup chamber having a substrate takeup means and an interleaf delivery means having an interleaf wound thereon which are provided therein, wherein said substrate web and said interleaf are continuously delivered from said substrate delivery means where said interleaf delivered is continuously wound on said interleaf takeup means and said web substrate delivered is continuously transported into a substrate-processing chamber through a steering roller where said web substrate is subjected to desired processing, the web substrate processed in the substrate-processing chamber is continuously transported into said substrate takeup chamber where the web substrate is wound through a steering roller on said substrate takeup means together with an interleaf delivered from said interleaf delivery means such that the web substrate and the interleaf are alternately wound on the substrate takeup means, wherein said substrate-processing apparatus is provided with a mechanism to detect transport abnormality of the interleaf in the substrate delivery chamber or/and the substrate takeup chamber whereby preventing the interleaf from suffering adhesion to the web substrate and also preventing the interleaf from being taken into the substrate processing chamber together with the web substrate.

P-0034[0034] As previously described, this substrate-processing apparatus makes it possible that a web substrate is continuously transported from the substrate delivery chamber into the substrate processing chamber while preventing the web substrate from being contacted with an interleaf which is delivered together with the web substrate where desired processing such as film formation is efficiently performed on the web substrate which is moving, and the substrate web thus processed in the substrate processing chamber is successively transported into the substrate takeup chamber where the web substrate is wound on the substrate takeup means while the processed surface of the web substrate being covered by an interleaf which is separately delivered without being contacted with the web substrate. Thus, there can be effectively obtained a rolled product comprising a web substrate having a processed surface (or having a deposited film formed thereon) and an interleaf which are alternately wound such that the processed surface (or the deposited film-bearing surface) of the web substrate is covered by the interleaf. This situation enables to efficiently and continuously form not only a high quality functional deposited film having satisfactory characteristics but also a high quality photovoltaic element (solar cell) having satisfactory characteristics on a web substrate at an improved yield.

P-0035[0035] The present invention also provides a substrate-processing method using the above substrate-processing apparatus.

P-0036[0036] The present invention includes the following aspects.

P-0037[0037] A first aspect of the present invention provides a substrate-processing apparatus comprising at least a substrate delivery chamber and a substrate-processing chamber, said substrate delivery chamber having a substrate delivery bobbin and an interleaf takeup bobbin provided therein, said substrate delivery bobbin having a roll comprising a web substrate and an interleaf alternately wound thereon,

P-0038[0038] wherein in said substrate delivery chamber, said web substrate and said interleaf are delivered from said substrate delivery bobbin while said web substrate delivered is transported into said substrate-processing chamber and said interleaf delivered is wound on said interleaf takeup bobbin, said web substrate transported into said substrate-processing chamber is subjected to desired processing in said substrate-processing chamber,

P-0039[0039] characterized in that said substrate-processing apparatus is provided with a mechanism for detecting transport abnormality of the interleaf in the substrate delivery chamber.

P-0040[0040] A second aspect of the present invention provides a substrate-processing apparatus comprising at least a substrate-processing chamber for processing a web substrate therein and a substrate takeup chamber having a substrate takeup bobbin and an interleaf delivery bobbin, wherein said web substrate processed in said substrate-processing chamber is transported into said substrate takeup chamber where said web substrate and an interleaf delivered from said interleaf delivery bobbin are alternately wound on said substrate takeup bobbin in a roll form, characterized in that said substrate-processing apparatus is provided with a mechanism for detecting transport abnormality of the interleaf in the substrate takeup chamber.

P-0041[0041] A third aspect of the present invention provides a substrate-processing apparatus comprising at least

P-0042[0042] a substrate delivery chamber having a substrate delivery bobbin and an interleaf takeup bobbin provided therein, said substrate delivery bobbin having a roll comprising a web substrate and an interleaf alternately wound;

P-0043[0043] a substrate-processing chamber for processing said web substrate therein; and

P-0044[0044] a substrate takeup chamber having a substrate takeup bobbin and an interleaf delivery bobbin provided therein,

P-0045[0045] wherein in said substrate delivery chamber, said web substrate and said interleaf are, delivered from said substrate delivery bobbin while said web substrate delivered is transported into said substrate-processing chamber and said interleaf delivered is wound on said interleaf takeup bobbin; said web substrate processed in said substrate-processing chamber is transported into said substrate takeup chamber, where said web substrate and an interleaf delivered from said interleaf delivery bobbin are alternately wound in a roll form on said substrate takeup bobbin,

P-0046[0046] characterized in that said substrate-processing apparatus is provided with at least either a mechanism for detecting transport abnormality of the interleaf in the substrate delivery chamber or a mechanism for detecting transport abnormality of the interleaf in the substrate takeup chamber.

P-0047[0047] A fourth aspect of the present invention provides a substrate-processing method comprising at least

P-0048[0048] (a) a step of delivering a web substrate and an interleaf from a substrate delivery bobbin provided in a substrate delivery chamber while said web substrate delivered from said substrate delivery bobbin is transported into a substrate-processing chamber and said interleaf delivered from said substrate delivery bobbin is wound on an interleaf takeup bobbin, said substrate delivery bobbin having a roll comprising said web substrate and said interleaf alternately wound, and

P-0049[0049] (b) a step of subjecting said web substrate transported into said substrate-processing chamber to desired processing in said substrate-processing chamber,

P-0050[0050] characterized in that in said step (a), transport abnormality of said interleaf in said substrate delivery chamber is detected by means of a transport abnormality-detecting mechanism.

P-0051[0051] A fifth aspect of the present invention provides a substrate-processing method comprising at least

P-0052[0052] (a) a step of introducing a web substrate into a substrate-processing chamber, where said web substrate is subjected to desired processing in said substrate-processing chamber, and

P-0053[0053] (b) a step of transporting said web substrate processed in said substrate-processing chamber into a substrate takeup chamber, where said web substrate is wound on a substrate takeup bobbin provided in said substrate takeup chamber together with an interleaf delivered from an interleaf delivery bobbin provided in said substrate takeup chamber such that said web substrate and said interleaf are alternately wound in a roll form,

P-0054[0054] characterized in that in said step (b), transport abnormality of said interleaf in said substrate takeup chamber is detected by means of a transport abnormality-detecting mechanism.

P-0055[0055] A sixth aspect of the present invention provides a substrate-processing method comprising at least

P-0056[0056] (a) a step of delivering a web substrate and an interleaf from a substrate delivery bobbin provided in a substrate delivery chamber while said web substrate delivered from said substrate delivery bobbin is transported into a substrate-processing chamber and said interleaf delivered from said substrate delivery bobbin is wound on an interleaf takeup bobbin, said substrate delivery bobbin having a roll comprising said web substrate and said interleaf alternately wound,

P-0057[0057] (b) a step of subjecting said web substrate transported into said substrate-processing chamber to desired processing in said substrate-processing chamber, and

P-0058[0058] (c) a step of transporting said substrate web processed in said substrate-processing chamber into a substrate takeup chamber, where said web substrate is wound on a substrate takeup bobbin provided in said substrate takeup chamber together with an interleaf delivered from an interleaf delivery bobbin provided in said substrate takeup chamber such that said web substrate and said interleaf are alternately wound in a roll form,

P-0059[0059] characterized in that in said step (a) or/and said step (c), transport abnormality of said interleaf in said substrate delivery chamber or/and said substrate takeup chamber is detected by means of a transport abnormality-detecting mechanism.

P-0060[0060] The mechanism of detecting transport abnormality of the interleaf in the present invention is desired to comprise a means for slack of the interleaf between the substrate delivery bobbin and the interleaf takeup bobbin in the substrate delivery chamber or/and a means for detecting slack of the interleaf between the interleaf delivery bobbin and the substrate takeup bobbin in the substrate takeup chamber. The term “slack” in the present invention is meant to include deflection.

P-0061[0061] The mechanism of detecting transport abnormality of the interleaf in the present invention may comprise a means for detecting adhesion between the web substrate and the interleaf. Further, The mechanism or means of detecting transport abnormality of the interleaf in the present invention may comprise a means for detecting rotation abnormality of the interleaf takeup bobbin or/and the interleaf delivery bobbin.

P-0062[0062] In any case, the transport abnormality-detecting mechanism may comprises a photo sensor, a physical sensor, or a rotation frequency detector for the interleaf takeup bobbin. Specifically, the transport abnormality-detecting mechanism may comprises a laser sensor or a limit switch.

P-0063[0063] In the present invention, it is desired for the substrate-processing apparatus to have a mechanism of preventing the interleaf from contacting with the web substrate at a portion other than the roll. Such mechanism may comprise a tray, a mesh or a bar-like member. It is possible that said mechanism and the transport abnormality-detecting mechanism comprises a common member.

P-0064[0064] The substrate-processing in the present invention includes film formation on a substrate, plasma processing of a substrate, and processing of a substrate including heat-treatment of said substrate. Representative specific examples of such substrate-processing are plasma chemical vapor deposition (plasma CVD) and sputtering.

P-0065[0065] Now, in the present invention, because such constitution as above described is employed, in the substrate delivery chamber, by detecting adhesion, electrostatic absorption or the like between the interleaf and the web substrate before the steering roller or by detecting slack of the interleaf, it is possible to previously prevent the interleaf from being taken into the substrate processing chamber situated next to the substrate delivery chamber which will be occurred when the winding of the interleaf becomes abnormal, whereby the roll-to-roll type substrate-processing apparatus can be maintained without being damaged due to transport abnormality of the interleaf. Further, in the substrate takeup chamber, by detecting pause of the interleaf which will be occurred when the interleaf is broken due to internal components such as the steering roller and the like in the substrate takeup chamber and terminating the transportation of the web substrate when the pause of the interleaf is occurred, whereby it is possible to previously prevent the yield and characteristics for the processed web substrate after the occurrence of the breakage at the interleaf from being decreased.

P-0066[0066] Thus, the present invention realizes a substrate-processing apparatus and a substrate-processing method which enable to improve not only the yield when a web substrate is processed but also the characteristics of a processed web substrate obtained. Particularly, the present invention realizes a film-forming apparatus and a film-forming method which enable to continuously and efficiently form not only a functional deposited film having satisfactory characteristics but also a photovoltaic element such as a solar cell having satisfactory characteristics on a web substrate at an improved yield.

P-0067[0067] The present invention includes a roll-to-roll type substrate-processing apparatus having at least either a mechanism of delivering a web substrate and an interleaf from a roll comprising said web substrate and said interleaf alternately wound and processing said web substrate or a mechanism of winding a processed substrate together with an interleaf in a roll form.

P-0068[0068] The substrate-processing apparatus can include roll-to-roll type film-forming apparatus such as a roll-to-roll type sputtering apparatus, a roll-to-roll type vacuum evaporation apparatus, a roll-to-roll type chemical vapor deposition (CVD) apparatus, a roll-to-roll type plating apparatus, and a roll-to-roll type coating apparatus, a roll-to-roll type etching apparatus, and a roll-to-roll type washing apparatus.

P-0069[0069] Further, The present invention includes a substrate-processing method having at least either a step of delivering a web substrate and an interleaf from a roll comprising said web substrate and said interleaf alternately wound and processing said web substrate or a step of winding a processed substrate together with an interleaf in a roll form.

P-0070[0070] The substrate-processing method can include film-forming method such a sputtering method, a vacuum evaporation method, a chemical vapor deposition (CVD) method, a plating method, and a coating method, an etching method, and a washing method.

P-0071[0071] The present invention is particularly effective when applied in the film-forming apparatus or method, especially when applied in the film-forming apparatus or method for forming a functional deposited film such as a semiconductor film. The reason for this is that transport abnormality of the interleaf is liable to impart various adverse effects to the characteristics of a film formed. Further, the transport abnormality of the interleaf is liable to impart various adverse effects to plasma. Therefore, the present invention is greatly effective when applied in the apparatus or method of processing a substrate using plasma. In addition, the present invention is also effective when applied in the substrate-processing apparatus or method in which a thermal energy is used.

P-0072[0072] In the following, description will be made of the contents of the transport abnormality of the interleaf and the mechanism of detecting the transport abnormality of the interleaf in the present invention.

P-0073[0073] Slack Abnormality of Interleaf:

P-0074[0074] Description will be made with reference to a typical example comprising a substrate takeup chamber in a roll-to-roll plasma CVD apparatus in which an electrically conductive web substrate is delivered, a plurality of functional films are sequentially formed on the web substrate delivered, and the web substrate having the functional deposited films formed thereon is wound together with an interleaf in a roll form such that the interleaf is wound to lay on the film-bearing surface of the web substrate.

P-0075[0075]FIG. 1 is a schematic diagram illustrating an inside constitution of the substrate takeup chamber. In FIG. 1, reference numeral <b>101</b> indicates the substrate takeup chamber, reference numeral <b>102</b> a web substrate, reference numeral <b>103</b> an interleaf in a normal state, reference numeral <b>103</b>′ an Interleaf in an abnormal state (a deflected state), reference numeral <b>104</b> a substrate takeup bobbin, reference numeral <b>105</b> an interleaf delivery bobbin, reference numeral <b>106</b> a steering roller, reference numeral <b>107</b> a gas gate, reference numeral <b>108</b> an exhaust pipe, reference numeral <b>109</b> a light emitting laser sensor, reference numeral <b>110</b> a light receiving laser sensor, and reference numeral <b>111</b> a tray as a mechanism of preventing a deflected interleaf <b>103</b> from contacting with the web substrate <b>102</b>.

P-0076[0076] In this embodiment, the web substrate <b>102</b> comprises a 0.15 mm thick SUS 4302 D web substrate of 355.6 mm in width and 1000 m in length. The web substrate is moved in a transportation direction shown by an arrow mark in FIG. 1 at a transportation speed of 1270 mm/minute while applying a tensile force of 80 Kg to the web substrate in the transportation direction. The interleaf <b>103</b> comprises a 0.05 mm thick polyimide film of 355.6 mm in width and 1000 m in length. The interleaf is arranged such that it is enfolded onto a film-forming face of the web substrate as shown by a solid line <b>103</b> in FIG. 1.

P-0077[0077] Under this condition, in the step wherein while the substrate web having a plurality of deposited films sequentially formed thereon is wound on the substrate takeup bobbin <b>104</b>, a new interleaf <b>103</b> is delivered from the interleaf delivery bobbin and is enfolded onto the film-bearing face of the web substrate, there is a fear of entailing such problem as will be described below.

P-0078[0078] That is, in the case where continuous film formation on the web substrate while moving the web substrate in the transportation direction is repeatedly conducted over a long period of time, when the rotation performance of the shaft of the interleaf delivery bobbin <b>105</b> fails due to deterioration and the like of the bearings and the speed for the interleaf to be enfolded becomes slower than that for the web substrate to be wound on the substrate takeup bobbin <b>104</b>, the interleaf starts gradually slacking and it eventually becomes to be in a state shown by a broken line <b>103</b>′ in FIG. 1.

P-0079[0079] In order to prevent occurrence of such problem as described in the above, a pair of a light emitting laser sensors <b>109</b> and a light receiving <b>110</b> laser sensor are arranged at respective prescribed positions as shown in FIG. 1 so that when the deflected interleaf crosses between the two laser sensors, an alarm is given and abnormality contents are indicated on a display panel (not shown), and when this crossing state of the interleaf between the two laser sensors is continued for more than 0.5 second, the discharge in all of the discharging chambers, the transportation of the web substrate and the rotation of the interleaf delivery bobbin are suspended. This constitution enables to prevent occurrence of a problem in that the deflected interleaf is mounted on the back face of the web substrate and pulled in the steering roller <b>106</b> whereby the interleaf is broken. And even when the process of processing the web substrate is suspended due to transport abnormality (slack abnormality) of the interleaf as above described, the cause of the transport abnormality of the interleaf can be promptly repaired by returning the interleaf to be in an normal state, where the process of processing the web substrate can be promptly restarted.

P-0080[0080] In this embodiment, as above described, the two laser sensor were used as the means of detecting transport abnormality of the interleaf (or as the means of detecting slack of the interleaf).

P-0081[0081] Besides, other photo sensors and physical sensors such as limit switch capable of detecting a fact when the interleaf is contacted with a given detecting portion may be selectively used.

P-0082[0082] For the position for the sensors as the means of detecting transport abnormality of the interleaf to be arranged, they are desired to be arranged at respective positions which are below the transportation path of the interleaf between the interleaf delivery bobbin and the substrate takeup bobbin and which do not hinder normal transportation of the Interleaf.

P-0083[0083] When such sensors as above described are arranged in such substrate delivery chamber as shown in FIG. 2 which will be later described, they are desired to be arranged at respective positions which are blow the transportation path of an interleaf between a substrate delivery bobbin and an interleaf takeup bobbin and which do not hinder normal transportation of the interleaf.

P-0084[0084] In the case where the sensors are arranged at said positions, the constitution detects a fact when the interleaf is present at a position where the interleaf is not be present. On the other hand, it is possible to take such a constitution as to detect a fact when the interleaf is present at a position where the interleaf is to be present. As an example in this case, there can be illustrated a constitution in that a pair of a light emitting laser sensor and a light receiving laser sensor are arranged between the interleaf delivery bobbin and the substrate takeup bobbin (or between the substrate delivery bobbin and the interleaf takeup bobbin) so as to sandwich the transportation path of the interleaf.

P-0085[0085] In a preferred embodiment, there is provided a mechanism comprising, for instance, a tray <b>111</b> (see, FIG. 1) for preventing the interleaf from contacting with the web substrate. This mechanism may comprise, besides said tray, a mesh member, a bar-like member or the like. Alternatively, it is possible for the mechanism to be integrated with a physical sensor or the like so that the mechanism can serve also as a means of detecting transport abnormality of the interleaf.

P-0086[0086] Adhesion Abnormality of Interleaf

P-0087[0087] Description will be made with reference to a typical example comprising a substrate delivery chamber in a roll-to-roll type plasma CVD apparatus in which an electrically conductive web substrate is delivered from a roll comprising said electrically conductive web substrate and an interleaf alternately wound, a plurality of functional films are sequentially formed on the web substrate delivered.

P-0088[0088]FIG. 2 is a schematic diagram illustrating an inside constitution of the substrate delivery chamber.

P-0089[0089] In FIG. 2, reference numeral <b>201</b> indicates the substrate delivery chamber, reference numeral <b>202</b> a web substrate, reference numeral <b>203</b> an interleaf in a normal state, reference numeral <b>203</b>′ an interleaf in an abnormal state (a slacked state), reference numeral <b>204</b> a substrate delivery bobbin, reference numeral <b>205</b> an interleaf takeup bobbin, reference numeral <b>206</b> a steering roller, reference numeral <b>207</b> a gas gate, reference numeral <b>208</b> an exhaust pipe, reference numeral <b>209</b> a light emitting laser sensor, reference numeral <b>210</b> a light receiving laser sensor, and reference numeral <b>211</b> a limit switch.

P-0090[0090] In the step wherein while the substrate web <b>202</b> prior to sequentially forming a plurality of deposited film thereon is delivered and the interleaf <b>203</b> is wound on the interleaf takeup bobbin <b>205</b>, when strong adhesion is present between the web substrate <b>202</b> and the interleaf <b>203</b> due to adhesion or electrostatic absorption of the interleaf, there is a fear such that the interleaf which is usually to be in a state shown by a solid line <b>203</b> in FIG. 2 becomes to be in such a state as shown by a broken line <b>203</b>′ in FIG. 2 and the interleaf is pulled in the steering roller <b>206</b>, whereby the interleaf is sandwiched between the web substrate and the steering roller, where the interleaf is broken or the interleaf is in a state such that the interleaf is mounted oh the back face of the web substrate and it is moved into a first film-forming chamber (not shown) situated next to the substrate delivery chamber together with the web substrate while maintaining this state.

P-0091[0091] In order to prevent occurrence such problem as above described, in addition to the laser sensors <b>209</b> and <b>210</b>, the limit switch <b>211</b> is arranged at a position above the steering roller <b>206</b> as shown in FIG. 2 so that when the interleaf adhered to the web substrate taps the limit switch, an alarm is given and abnormality contents are indicated on a display panel (not shown), and when the state of tapping the limit switch is continued for more than 0.5 second, the discharge in all of the discharging chambers, the transportation of the web substrate and the rotation of the interleaf takeup bobbin are suspended. By this, it is possible to prevent occurrence of a problem in that the breakage of the interleaf due to the adhesion of the interleaf to the web substrate or the Interleaf is taken into the first film-forming chamber situated next to the substrate delivery chamber. And even when the process of processing the web substrate is suspended due to transport abnormality (adhesion abnormality) of the interleaf as above described, the cause of the transport abnormality of the interleaf can be promptly repaired by returning the interleaf to be in an normal state, where the process of processing the web substrate can be promptly restarted.

P-0092[0092] In this embodiment, instead of the limit switch or in combination with the laser sensors, it is possible to use any of the foregoing transport abnormality-detecting mechanism. It is also possible to use the foregoing mechanism of preventing the interleaf from contacting with the web substrate.

P-0093[0093] Further, in the case where there is considered an occasion such that the interleaf will be broken due to a certain cause and the interleaf which is originally to be wounded on the interleaf takeup bobbin will be transported while being adhered to the web substrate, it is desired to examine whether or not foreign matter (the interleaf) is adhered on the surface of the web substrate by using a photo sensor or the like capable of detecting light reflected from the surface of the web substrate instead of or in addition to the limit switch.

P-0094[0094] In the case where such photo sensor capable of detecting light reflected from the substrate is installed in the substrate-processing apparatus having such substrate transportation path as shown in FIG. 1 or FIG. 2, it is desired to arrange a photo sensor having a light emitting portion and a light receiving portion so that light emitted from the light emitting portion of the photo sensor is irradiated to the web substrate and light reflected from the web substrate is impinged in the light receiving portion of the photo sensor. For the position for the photo sensor to be arranged in the substrate delivery chamber, it is desired to be a position above the substrate transportation path in the vicinity of the gas gate <b>207</b> (that is, immediately before the web substrate gets in the gas gate) in a viewpoint of preventing the interleaf from entering in the processing chamber (or the film-forming chamber) and also a position above the right side of the substrate transportation path between the substrate delivery bobbin <b>204</b> and the steering roller <b>206</b> in a viewpoint of preventing the interleaf from being taken in the steering roller and broken. It is preferred that said photo sensor is arranges at each of these two positions. In the case of the substrate takeup chamber, it is preferred that the photo sensor is arranged at a position above the substrate transportation path in the vicinity of the steering roller <b>106</b> (that is, immediately before the web substrate reaches the steering roller).

P-0095[0095] Revolution Abnormality of Interleaf Bobbin:

P-0096[0096] Description will be made of a means of detecting revolution abnormality of the interleaf delivery bobbin <b>105</b> shown in FIG. 1 or the interleaf takeup bobbin <b>205</b> shown in FIG. 2 in the substrate delivery chamber or the substrate takeup chamber in a roll-to-roll type plasma CVD apparatus in which an electrically conductive web substrate is delivered from a roll comprising said electrically conductive web substrate and an interleaf alternately wound, a plurality of functional films are sequentially formed on the web substrate delivered, and the web substrate having functional deposited films formed thereon is wound in a roll form together with an interleaf such that the interleaf is laid on the film-bearing face of the web substrate.

P-0097[0097] The term “revolution abnormality” in the present invention means a sudden change in the revolution speed of the interleaf bobbin (the interleaf takeup bobbin and the interleaf delivery bobbin). The “sudden change” is meant to include reverse rotation, stopping and the like.

P-0098[0098] In FIG. 3, there is shown an example of a rotation system of an interleaf bobbin [an interleaf delivery bobbin (<b>105</b>) or an interleaf takeup bobbin (<b>205</b>)] used in a substrate-processing apparatus according to the present invention.

P-0099[0099] In FIG. 3, reference numeral <b>301</b> indicates a chamber wall, reference numeral <b>302</b> an interleaf bobbin (an interleaf delivery bobbin or an interleaf takeup bobbin), reference numeral <b>303</b> a vacuum magnetic sealing flange, reference numeral <b>304</b> a coupling, reference numeral <b>305</b> a clutch, reference numeral <b>306</b> a coupling, reference numeral <b>307</b> a motor, reference numeral <b>308</b> a proximity sensor, and reference numeral <b>309</b> a dog.

P-0100[0100] As shown in FIG. 3, as a means of detecting revolution abnormality of the interleaf bobbin <b>302</b> from the atmospheric pressure side, a pair of identifiable dogs <b>309</b> are arranged at the coupling <b>304</b> provided between the vacuum magnetic sealing flange <b>303</b> and the clutch <b>305</b> and a proximity sensor <b>308</b> is arranged right under the coupling at which the pair of identifiable dogs <b>309</b> are arranged.

P-0101[0101]FIG. 4 is a schematic principle view for explaining the mechanism of detecting rotation abnormality (reverse rotation or stopping) of the interleaf bobbin.

P-0102[0102] Specifically, as shown in FIG. 4, the pair of identifiable dogs <b>309</b> (dog A and dog B) are arranged so as to have a positional relationship of 90° between them, and they are rotated at the same rotation speed as that of the interleaf.

P-0103[0103] Now, in FIG. 4, in the case where the duration since the dog A has passed the proximity sensor <b>308</b> until the dog B passes the proximity sensor is made to be t_ABand the duration since the dog B has passed the proximity sensor until the dog A passes the proximity sensor is made to be t_BA, when the equation t_BA−(t_AB×2) provided a negative value, it is determined that the interleaf was reversed. When the equation provides a positive value, it is determined that the interleaf bobbin is being normally rotated.

P-0104[0104] Separately, in the case where the equation t_BA+t_α (t_α: an optionally set time) is timer-set as a stopping detection time, when the stopping time is time-upped or neither the dog A nor the dog B passe the proximity sensor, it is determined that the rotation of the interleaf bobbin is stopped.

P-0105[0105] In addition, in order to avoid the malfunction, the system is designed not to detect revolution abnormality of the interleaf bobbin for <b>60</b> seconds after the commencement of the transportation of the web substrate. This means that the detection of revolution abnormality of the interleaf bobbin is performed after the transportation of the web substrate became constant at a prescribed transportation speed. Further, the system is designed such that the detection of revolution abnormality of the interleaf bobbin is performed other than the time when the web substrate is usually transported.

P-0106[0106] Now, when revolution abnormality of the interleaf bobbin is detected, an alarm is given and abnormality contents are indicated on a display panel (not shown), and when the abnormal state is continued for more than <b>1</b> second, the discharge in all of the discharging chambers, the transportation of the web substrate and the rotation of the interleaf bobbin are suspended. By this, it is possible to prevent occurrence of a problem in that the breakage of the interleaf due to revolution abnormality of the interleaf bobbin or the interleaf is taken into the first film-forming chamber situated next to the substrate delivery chamber. This situation previously prevents the film-forming apparatus from being damaged. And even when the process of processing the web substrate is suspended due to revolution abnormality of the interleaf bobbin (that is, transport abnormality of the interleaf) as above described, the cause of the abnormality of the interleaf can be promptly repaired by returning the interleaf to be in an normal state, where the process of processing the web substrate can be promptly restarted.

P-0107[0107] In this embodiment, the detection of revolution abnormality of the interleaf bobbin (the interleaf takeup bobbin and the interleaf delivery bobbin) is performed on the atmospheric pressure side (that is, outside the chamber). However, it is possible to designed such that the detection of revolution abnormality of the interleaf bobbin is performed in the vacuum side (that is, in the chamber).

P-0108[0108] In the following, the present invention will be described in more detail with reference to examples. It should be understood that these examples are only for illustrative purposes and the scope of the present invention is not restricted to these examples.

EXAMPLE 1

P-0109[0109] In this example, using the roll-to-roll type DC magnetron sputtering apparatus shown in FIG. 5, a two-layered back reflecting layer (<b>602</b>, <b>603</b>) of a single cell type amorphous silicon solar cell shown in FIG. 6 was formed. In FIG. 6, reference numeral <b>601</b> indicates a substrate, reference numeral <b>602</b> a metal reflecting layer, reference numeral <b>603</b> a transparent oxide layer, each of reference numerals <b>604</b> to <b>608</b> a semiconductor layer, reference numeral <b>609</b> a transparent electrically conductive layer, and reference numeral <b>610</b> a collecting electrode (or a grid electrode).

P-0110[0110] In this example, in substrate takeup chamber <b>504</b> of the apparatus shown in FIG. 5 (the substrate takeup chamber <b>504</b> is corresponding to the substrate takeup chamber <b>101</b> shown in FIG.1), an interleaf slack abnormality-detecting mechanism comprising a pair of a light emitting laser sensor <b>511</b> and a light receiving laser sensor <b>512</b> was provided, and an interleaf bobbin revolution abnormality (reverse rotation, stopping)—detecting mechanism of the configuration shown in FIG. 3 was provided in the revolution system of interleaf delivery bobbin <b>509</b> (which is corresponding to the interleaf delivery bobbin <b>105</b> in FIG. 1).

P-0111[0111] First, a substrate delivery bobbin <b>503</b> having a sufficiently-cleaned stainless web substrate <b>502</b> (width: 355.6 mm, thickness: 0.15 mm, length: 1000 m) wound thereon in a roll form with no interleaf was set in substrate delivery chamber <b>501</b> having a steering roller <b>505</b> provided therein. Reference numeral <b>504</b> indicates an interleaf takeup bobbin. The interleaf takeup bobbin <b>504</b> was not used in this example.

P-0112[0112] In the substrate takeup chamber <b>506</b>, there were arranged a substrate takeup bobbin <b>508</b> having anything wound thereon and an interleaf delivery bobbin <b>509</b> having an interleaf <b>507</b> [comprising a polyester film with aluminum vacuum-deposited thereon (width: 355.6 mm, thickness: 0.05 mm, length: 1000 m)] wound thereon in a roll form.

P-0113[0113] The web substrate was delivered from the substrate delivery bobbin <b>503</b>, followed by passing it through film-forming chambers <b>513</b> and <b>514</b> to enter into the substrate takeup chamber <b>506</b> where the beginning portion of the web substrate was fixed to and wound on the substrate takeup bobbin <b>508</b>. The transportation system of the web substrate was adjusted so that the web substrate could be continuously transported from the substrate delivery chamber to the substrate takeup chamber without being deflected.

P-0114[0114] Then, the inside of the apparatus was evacuated until the inner pressure became less than <b>0</b>.<b>01</b> Pa by means of a vacuum pump (not shown).

P-0115[0115] Thereafter, through respective gas feed pipes <b>531</b>-<b>535</b>, inert gas (argon gas) was supplied into the metal reflecting layer-forming chamber <b>513</b> and the transparent oxide layer-forming chamber <b>514</b> at a flow rate of 50 sccm. While maintaining this state, the openings of exhaust valves (not shown) were adjusted to maintain the inner pressure of each chamber at 0.3 Pa. After this, using heater units <b>526</b>-<b>530</b>, the thermocouples were contacted with the back face (the non-film-forming face) of the web substrate and the web substrate was heated to and maintained at 250° C. while performing temperature control. Successively, the web substrate started moving at a transportation speed of 1270 mm/minute while applying a tensile force of 60 Kg thereto.

P-0116[0116] In the metal reflecting layer-forming chamber <b>513</b>, a target <b>520</b> comprising an aluminum (purity: 99.99 wt. %) was used. And by applying a D.C. power of 2 KW from a D.C. power source <b>537</b> to a cathode electrode <b>515</b> to sputter the target <b>520</b>, a 0.2 μm thick aluminum metal reflecting layer <b>602</b> on the web substrate <b>502</b> (as the substrate <b>601</b> in FIG. 6). In the transparent oxide layer-forming chamber <b>514</b>, targets <b>521</b>-<b>524</b> each comprising a zinc oxide (ZnO) were used. And by applying a D.C. power of 1.5 KW from each of D.C. power sources <b>538</b>-<b>541</b> to each of cathode electrodes <b>516</b>-<b>519</b> to sputter the targets <b>521</b>-<b>524</b>, a 1.0 μm thick transparent oxide (zinc oxide) layer <b>603</b> on the metal reflecting layer <b>602</b>. Thus, there was formed a two-layered back reflecting layer (comprising the aluminum metal reflecting layer <b>602</b> and the transparent oxide (zinc oxide) layer <b>603</b>) on the web substrate <b>502</b> as the substrate <b>601</b> (see, FIG. 6).

P-0117[0117] In FIG. 5, each of reference numerals <b>542</b>-<b>550</b> indicates a substrate-transporting magnet roller, reference numeral <b>525</b> a gas gate, and reference numeral <b>536</b> a gate gas feed pipe.

P-0118[0118] The once (one roll) film formation time was about 10 hours. During the once film formation, by means of the interleaf slack abnormality-detecting mechanism (comprising the light emitting laser sensor <b>511</b> and the light receiving laser sensor <b>512</b> and the interleaf bobbin revolution abnormality-detecting mechanism of the configuration shown in FIG. 3, detection was conducted of whether or not transport abnormality of the interleaf was occurred. However, no transport abnormality of the interleaf was occurred during the once film formation. Then, the film formation was repeated for 100 rolls (about 1000 hours), during which detection was conducted of whether or not transport abnormality of the interleaf was occurred in the same manner as in the above, and as a result, transport abnormality of the interleaf due to slack of the interleaf was detected. When the transport abnormality was detected, the discharge in all the film-forming chambers, the transportation of the web substrate, and the rotation of the interleaf bobbin were suspended, and through a viewing port (not shown) in the substrate takeup chamber <b>506</b>, the inside of the substrate takeup chamber was observed. As a result, it was found that the deflected interleaf was stopped before the steering roller <b>510</b>, and breakage or the like were not occurred at the interleaf. Thereafter, immediately after the substrate takeup chamber <b>506</b> was leaked and the interleaf was adjusted to be in a normal state, the apparatus was promptly returned to be in a state capable of performing the film formation to restart the formation of the two-layered back reflecting layer.

P-0119[0119] Based on this result, it was found that the mechanism of detecting transport abnormality of the interleaf according to the present invention is practically effective for previously preventing occurrence of trouble(s) in the film-forming apparatus due to transport abnormality of the interleaf.

EXAMPLE 2

P-0120[0120] In this example, using one of the rolls obtained in Example 1, each roll comprising the web substrate (<b>502</b>) having the two-layered back reflecting layer (comprising the aluminum metal reflecting layer <b>602</b> and the transparent oxide (zinc oxide) layer <b>603</b>) formed thereon wound together with the interleaf (<b>507</b>) [comprising the polyester film with aluminum vacuum-deposited thereon] in a roll form, the semiconductor layers <b>604</b>-<b>608</b> of the single cell type amorphous silicon solar cell shown in FIG. 6 were sequentially formed on the two-layered back reflecting layer by the roll-to-roll type plasma CVD apparatus shown in FIG. 7.

P-0121[0121] In FIG. 7, reference numeral <b>701</b> indicates a substrate delivery chamber (having such constitution as shown in FIG. 2), reference numeral <b>702</b> a web substrate (corresponding to the web substrate <b>502</b> in Example 1), reference numeral <b>703</b> an interleaf (corresponding to the interleaf <b>507</b> in Example <b>1</b>), reference numeral <b>704</b> a substrate delivery ribbon (comprising aforesaid one of the rolls obtained in Example <b>1</b>), reference numeral <b>705</b> an interleaf takeup bobbin, reference numeral <b>706</b> a steering roller, reference numeral <b>707</b> a light emitting laser sensor, reference numeral <b>708</b> a light receiving laser sensor, reference numeral <b>709</b> a limit switch.

P-0122[0122] Reference numeral <b>717</b> indicates a film-forming chamber for~forming an n-type semiconductor layer using RF power, reference numeral <b>718</b> a film-forming chamber for forming an i-type semiconductor layer using RF power, reference numeral <b>719</b> a film-forming chamber for forming an i-type semiconductor layer using microwave (MW) power, reference numeral <b>720</b> a film-forming chamber for forming an i-type semiconductor layer using RF power, and reference numeral <b>721</b> a film-forming chamber for forming a p-type semiconductor layer using RF power. Reference numeral <b>724</b> indicates a discharge region provided in the film-forming chamber <b>719</b>.

P-0123[0123] Reference numeral <b>710</b> indicates a substrate takeup chamber (having such constitution as shown in FIG. 1), reference numeral <b>711</b> an interleaf, reference numeral <b>712</b> a substrate takeup bobbin (having anything wound thereon), reference numeral <b>713</b> an interleaf delivery bobbin having the interleaf <b>711</b> wound thereon in a roll form, reference numeral <b>714</b> a steering roller, reference numeral <b>715</b> a light emitting laser sensor, and reference numeral <b>716</b> a light receiving laser sensor.

P-0124[0124] In this example, in the substrate delivery chamber <b>701</b> of the apparatus shown in FIG. 7, an interleaf slack abnormality-detecting mechanism comprising a pair of a light emitting laser sensor <b>707</b> and a light receiving laser sensor <b>708</b> and an interleaf adhesion-detecting mechanism comprising a limit switch <b>709</b> were arranged. In addition, an interleaf bobbin revolution abnormality-detecting mechanism of the configuration shown in FIG. 3 was provided in the revolution system of the interleaf takeup bobbin <b>705</b>.

P-0125[0125] Further, in the substrate takeup chamber <b>710</b>, an interleaf slack abnormality-detecting mechanism comprising a pair of a light emitting laser sensor <b>715</b> and a light receiving laser sensor <b>716</b> was arranged. In addition, an interleaf bobbin revolution abnormality-detecting mechanism of the configuration shown in FIG. 3 was provided in the revolution system of the interleaf delivery bobbin <b>713</b>.

P-0126[0126] The film formation using the apparatus shown in FIG. 7 was conducted as follows.

P-0127[0127] In the substrate delivery chamber <b>701</b>, a substrate delivery bobbin <b>704</b> having the foregoing one of the rolls obtained in Example 1 thereon was set. In the substrate takeup chamber <b>710</b>, a substrate takeup bobbin <b>712</b> having anything wound thereon and an interleaf delivery bobbin <b>713</b> having an interleaf <b>711</b> [comprising a polyester film with aluminum vacuum-deposited thereon (width: 355.6 mm, thickness: 0.05 mm, length: 1000 m)] wound thereon in a roll form were set.

P-0128[0128] The web substrate <b>702</b> having the two-layered back reflecting layer thereon was delivered together with the interleaf <b>703</b> from the substrate delivery bobbin <b>703</b>, where the interleaf was delivered separately from the web substrate <b>702</b> and the interleaf delivered was successively wound on the interleaf takeup bobbin <b>705</b>, and the web substrate <b>702</b> delivered was followed by passing through the film-forming chambers <b>717</b>-<b>721</b> to enter into the substrate takeup chamber <b>710</b> where the beginning portion of the web substrate was fixed to and wound on the substrate takeup bobbin <b>712</b>. In the takeup chamber <b>710</b>, upon winding the web substrate <b>702</b> on the substrate takeup bobbin <b>712</b>, the interleaf <b>711</b> was delivered from the interleaf delivery bobbin <b>713</b> and it was wound on the substrate takeup bobbin <b>712</b> together with the web substrate <b>702</b> so that the film-forming face of the web substrate was covered by the interleaf.

P-0129[0129] The transportation system of the web substrate was adjusted so that the web substrate could be continuously transported from the substrate delivery chamber to the substrate takeup chamber without being deflected.

P-0130[0130] Then, the inside of the apparatus was evacuated until the inner pressure of each of the film-forming chambers <b>717</b>-<b>721</b> became less than 1 mTorr (1.33×10⁻¹Pa) by means of a vacuum pump (not shown).

P-0131[0131] Thereafter, through respective gate gas feed pipes <b>747</b>-<b>752</b>, inert gas (helium gas) was flown into respective gas gates <b>727</b>-<b>732</b> at a flow rate of 150 sccm. While maintaining this state, the openings of exhaust valves (not shown) were adjusted to maintain the inner pressure of each film-forming chamber at 1 Torr (133 Pa). After this, using heater units <b>733</b>-<b>737</b>, the web substrate was heated to and maintained at 300° C. while performing temperature control. While maintaining this state, baking was conducted for 4 hours to release impurity gases present in each of the film-forming chambers <b>717</b>-<b>721</b>. Then, each of the heater units <b>733</b>-<b>737</b> was regulated so that the film-forming temperature in each film-forming chamber became a prescribed temperature, and thereafter, the inside of each film-forming chamber was heated by means of the corresponding heater unit.

P-0132[0132] Thereafter, the introduction of the helium gas was terminated, and through gas feed pipes <b>742</b>-<b>746</b>, prescribed film-forming raw material gas was introduced into each of the film-forming camber <b>717</b>-<b>721</b> at a prescribed flow rate. Further, through the gate gas feed pipes <b>747</b>-<b>752</b>, hydrogen gas (H₂gas) was flown into the gas gates <b>727</b>-<b>732</b> at a flow rate of 1000 sccm.

P-0133[0133] Successively, the web substrate started moving at a transportation speed of 1270 mm/minute while applying a tensile force of 80 Kg thereto.

P-0134[0134] Thereafter, to each of cathode electrodes <b>722</b>, <b>723</b>, <b>725</b> and <b>726</b> in the film-forming chambers <b>717</b>, <b>718</b>, <b>720</b> and <b>721</b>, a prescribed RF (high frequency) power was applied from each of RF power sources <b>753</b>, <b>754</b>, <b>755</b> and <b>756</b>. And a prescribed microwave power from a microwave power source (not shown) and a prescribed RF bias power from an RF power source (not shown) were introduced into the discharge region <b>724</b>. Thus, on the two-layered back reflecting layer of the web substrate which was moving, there were continuously formed an n-type semiconductor layer <b>604</b> comprising an amorphous silicon (a-Si) material in the film-forming chamber <b>717</b>, an i-type semiconductor layer <b>605</b> comprising an a-Si material in the film-forming chamber <b>718</b>, an i-type semiconductor layer <b>606</b> comprising an amorphous silicon-germanium (a-SiGe) material in the film-forming chamber <b>719</b>, an i-type semiconductor layer <b>607</b> comprising an a-Si material in the film-forming chamber <b>720</b>, and a p-type semiconductor layer <b>608</b> comprising a microcrystalline silicon (μc-Si) material in the film-forming chamber <b>721</b>.

P-0135[0135] In FIG. 7, each of reference numerals <b>757</b>-<b>770</b> indicates a substrate-transporting magnet roller.

P-0136[0136] The once (one roll) film formation time was about <b>10</b> hours. During the once film formation, by means of the interleaf slack abnormality-detecting mechanism comprising the light emitting laser sensor <b>707</b> and the light receiving laser sensor <b>708</b> and the interleaf adhesion-detecting mechanism comprising the limit switch <b>709</b> which were provided in the substrate delivery chamber <b>701</b> and the interleaf bobbin revolution abnormality-detecting mechanism of the configuration shown in FIG. 3 which was provided in the revolution system of the interleaf takeup bobbin <b>705</b> in the substrate delivery chamber <b>701</b>, and also by means of the interleaf slack abnormality-detecting mechanism comprising the light emitting laser sensor <b>715</b> and the light receiving laser sensor <b>716</b> which was provided in the substrate takeup chamber <b>710</b> and the interleaf bobbin revolution abnormality-detecting mechanism of the configuration shown in FIG. 3 which was provided in the revolution system of the interleaf delivery bobbin <b>713</b> of the substrate takeup chamber <b>710</b>, detection was conducted of whether or not transport abnormality of the interleaf was occurred. However, no transport abnormality of the interleaf was occurred during the once film formation.

P-0137[0137] Then, the film formation was repeated for 100 rolls (about 1000 hours), during which detection was conducted of whether or not transport abnormality of the interleaf was occurred in the same manner as in the above, and as a result, in the substrate delivery chamber <b>701</b>, transport abnormality of the interleaf due to adhesion of the interleaf <b>705</b> (comprising the polyester film with aluminum vacuum-deposited thereon) was detected. When the transport abnormality was detected, the discharge in all the film-forming chambers, the transportation of the web substrate, and the rotation of the interleaf bobbins were suspended, and through a viewing port (not shown) in the substrate delivery chamber <b>701</b>, the inside of the substrate delivery chamber was observed. As a result, it was found that the adhered interleaf was stopped before the steering roller <b>706</b>, and breakage or the like were not occurred at the interleaf.

P-0138[0138] Separately, besides the film-formation wherein the adhesion of the interleaf was detected, in the film formation another roll, transport abnormality of the interleaf due to slack thereof was detected in the substrate delivery chamber <b>701</b>. When the transport abnormality was detected, the discharge in all the film-forming chambers, the transportation of the web substrate, and the rotation of the interleaf bobbins were suspended, and through the viewing port (not shown) in the substrate delivery chamber <b>701</b>, the inside of the substrate delivery chamber was observed. As a result, it was found that the deflected interleaf was stopped before the entrance of the gas gate <b>727</b> between the substrate delivery chamber <b>701</b> and the film-forming chamber <b>717</b> situated next to the substrate delivery chamber and the interleaf was not taken into the film-forming chamber <b>717</b>. Thereafter, immediately after the substrate delivery chamber <b>701</b> was leaked and the bearings (not shown) of the interleaf takeup bobbin <b>705</b> were replaced by new bearings, the apparatus was returned to be in a state capable of performing the film formation to restart the formation of the semiconductor layers <b>604</b>-<b>608</b>.

P-0139[0139] Based on the results, it was found that the mechanism of detecting transport abnormality of the interleaf according to the present invention is practically effective for previously preventing occurrence of trouble(s) in the film-forming apparatus due to transport abnormality of the interleaf.

P-0140[0140] Using randomly selected one of the rolls obtained in the above, on the p-type semiconductor layer <b>608</b> of the substrate, a transparent electrically conductive layer <b>609</b> and a grid electrode <b>610</b> were sequentially formed by a conventional manner to obtain a number of single cell type amorphous silicon solar cells. These solar cells were found to be satisfactory in solar

REFERENCE EXAMPLE

P-0141[0141] In this reference example, the procedures of Example 2 were repeated, except that without providing such mechanisms of detecting transport abnormality of the interleaf as used in Example 2 in the substrate delivery chamber and the substrate takeup chamber, the semiconductor layers <b>604</b>-<b>608</b> were sequentially formed on the web substrate. That is, in this reference example, in order to substitute those detecting mechanisms used in Example 2, without employing such sequence in Example 2 in which the discharge in all the film-forming chambers, the transportation of the web substrate and the rotation of the interleaf bobbins are suspended when transport abnormality of the interleaf is detected, there were used means which gives an alarm and indicates contents of transport abnormality of the interleaf when the transport abnormality of the interleaf is occurred.

P-0142[0142] When slack abnormality of the interleaf was occurred in the substrate delivery chamber <b>701</b>, an alarm was given. After <b>10</b> seconds since the alarm was given, the operator suspended the discharge in all the film-forming chambers, the transportation of the web substrate, and the rotation of the interleaf bobbins. Then, through the viewing port (not shown) in the substrate delivery chamber <b>701</b>, the inside of the substrate delivery chamber was observed. As a result, it was found that the deflected interleaf was taken into the gas gate <b>727</b> between the substrate delivery chamber <b>701</b> and the film-forming chamber <b>717</b> situated next to the substrate delivery chamber in such a state that the interleaf was mounted on the web substrate. And the inside of the apparatus was leaked and the inside of the film-forming chamber <b>717</b> was observed. As a result, it was found that the interleaf reached near the center of the inside of the film-forming chamber, where the interleaf was melted by the heat from the heater unit and the aluminum of the interleaf was deposited on the inner wall face of the film-forming chamber and also on the components in the film-forming chamber. Thus, the film formation in the apparatus could not be restarted.

P-0143[0143] As apparent also from the results in this reference example, it is understood that the mechanism of detecting transport abnormality of the interleaf according to the present invention is indispensable and practically effective in a roll-to-roll type substrate-processing apparatus in order to previously prevent occurrence of trouble(s) due to transport abnormality of the interleaf in the apparatus.

P-0144[0144] As detailed in the above, in the present invention, by installing the foregoing mechanism(s) of detecting transport abnormality of the interleaf in a roll-to-roll type substrate-processing apparatus, it is possible to previously prevent occurrence of trouble(s) due to transport abnormality of the interleaf during the processing of the substrate which is continuously conducted over a long period of time whereby preventing the apparatus from being damaged. It is also possible to previously prevent occurrence of any troubles due to breakage or the like of the interleaf. This situation makes it possible to realize a substrate-processing apparatus and a substrate-processing method which enable to efficiently and continuously process a given substrate in a desired state at an improved yield. In addition, according to the present invention, it is possible to realize a film-forming apparatus and a film-forming method which enable to efficiently and continuously form not only a high quality functional deposited film (or a semiconductor film) having satisfactory characteristics but also a high quality photovoltaic element (or a high quality solar cell) having satisfactory characteristics on a long substrate at an improved yield.