Antistatic film, spacer using it and picture display unit

0001The present invention relates to a method for manufacturing an antistatic film to be installed in an airtight vessel containing an electron source of an electron-generating device such as a picture display unit.

0002A flat display unit using an electron-emitting device has, as shown in Japanese Patent Application Laid-Open No. <patcit id="pcit0001" dnum="JPH10284286B"><text>H10-284286</text></patcit>, a spacer called as the spacer or a rib installed therein, which is a structural support resistant to ambient pressure for keeping the inside of the unit into a high vacuum.

0003<figref idref="f0006">FIG. 7</figref> is a cross-sectional schematic view of an image-forming apparatus using many electron-emitting devices. Reference numeral 101 denotes a rear plate, reference numeral 102 a sidewall and reference numeral 103 a faceplate, and an airtight vessel is formed by the rear plate 101, the side wall 102 and the face plate 103. A spacer 107b that is a structural support resistant to ambient pressure in the airtight vessel has a low-resistivity film 110 thereon, and is connected to wiring 109 through an electroconductive frit 108.

0004An electron-emitting device 104 is formed on a rear plate 101, and a phosphor 105 and a metal back 106 are formed on a face plate. Objects of providing a metal back 106 are to improve a utilization factor of light by mirror-reflecting a light emitted from a phosphor 105; to protect the phosphor 105 from the collision of negative ions; to work as an electrode for applying an electron beam-accelerating voltage; and to work as a conducting path for electrons after having excited the phosphor 105.

0005A spacer 107a shows the electrostatically charged state of the spacer, and shows a state in which electrostatic charge (positive electrostatic charge in the drawing) is caused by collision of one part of electrons emitted from an electron source around it. Here, the spacer 107a shows the electrostatically charged state of the spacer when having no antistatic film 112 installed thereon, and thus, the thickness of a low-resistivity film is drawn more thickly than the low-resistivity film 110 contacting with the antistatic film 112 of the spacer 107b, for convenience in illustration.

0006When a spacer 107a is positively charged with electricity as described above, electrons emitted from an electron-emitting device 104 that is an electron source are drawn to a spacer side, for example, like an electron trajectory 111a, and consequently impair the quality of a displayed image.

0007In order to solve the problem, there is a proposition of arranging an antistatic film 112 on a spacer 107b, eliminating the charge by passing a micro electrical current through the surface, and thereby making electrons draw a predetermined trajectory such as an electron trajectory 111b, without being drawn to the spacer. There is also a proposition, as shown in Japanese Patent Application Laid-Open No. <patcit id="pcit0002" dnum="JP2001143620A"><text>2001-143620</text></patcit>, of providing unevenness on the surface of a spacer glass substrate to make an effective secondary emission coefficient less than that with a flat spacer surface, and to effectively inhibit the electrostatic charge of the spacer surface.

0008Furthermore, Japanese Patent Application Laid-Open No. <patcit id="pcit0003" dnum="JPH10284283B"><text>H10-284283</text></patcit> proposes a spacer coated with an electrostatic charge-mitigating film containing aluminum nitride and/or aluminum oxide, and noble metals such as gold, palladium and platinum, by binary simultaneous sputtering with the use of an aluminum target and a noble metal target, and of a mixed gas of argon and nitrogen or oxygen as a gas for forming a film.

0009However, it has become clear that the spacers shown in the above described conventional examples cause variation in the performance of the function for eliminating electrostatic charge.

0010In particular, when a temperature distribution is formed in the spacer, the distribution of resistivity is also formed due to the temperature characteristic of the resistivity of the antistatic film. The variation of resistivity leads to the variation in the diselectrification function.

0011Specifically, in a flat display panel, the instability of a display image results from temperature distribution in a panel plane, which is caused by a temperature difference between a face plate and a rear plate.

0012In addition, a conventional method of forming an antistatic film containing a plurality of elements by sputtering simultaneously a plurality of different material targets (for example, binary sputtering with the use of two materials) might cause variation in the resistivity of an antistatic film depending on each film-forming batch even when film-forming conditions (background, sputtering pressure, gas flow rate and target electrification power) are uniformized.

0013In order to uniformize resistivity, target electrification powers supplied to different material targets are required to be adjusted to each, which is complicated, and the operation is not always highly reproducible. In particular, in binary sputtering, when there is a large difference between target electrification powers, so-called cross contamination can not be avoided, which is a phenomenon that a more powerfully electrified target material deposits on the surface of a less powerfully electrified target material.

0014Document <patcit id="pcit0004" dnum="EP1203788A1"><text>EP 1 203 788 A1</text></patcit> discloses a semiconductive polyvinylidene fluoride resin composition comprising 100 parts by weight of a polyvinylidene fluoride resin, 0.03 to 10 parts by weight of at least one tetraalkylammonium salt selected from the group consisting of tetraalkylammonium sulfates and tetraalkylammonium sulfites, and 1 to 20 parts by weight of conductive carbon black, and a formed or molded product composed of the semiconductive polyvinylidene fluoride resin composition.

0015Document <patcit id="pcit0005" dnum="US20030048067A1"><text>US2003/0048067 A1</text></patcit> discloses a composition for forming a coating layer comprising a metallic oxide particulate, a coloring agent, and a silane coupling agent. The metallic oxide particulate is at least one metallic oxide selected from the group consisting of indium tin oxide, antimony tin oxide, aluminum zinc oxide, SnO₂, In₂O₃, and Sb₂O₃. The coloring agent includes an organic or an inorganic pigment, or a metal complex.

0016An object of the present invention is to provide a method of manufacturing an antistatic film having superior controllability for a resistivity value, stability and reproducibility, and the adequate temperature characteristics of resistance.

0017According to the present invention, this is accomplished by the subject-matter as defined in independent claim 1.

0018An advantageous modification thereof is defined in claim 2. <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a schematic view showing the cross-sectional shape of an antistatic film which can be manufactured according to the present invention, observed with a TEM (a transmission electron microscope);</li><li><figref idref="f0002">FIG. 2</figref> is a perspective view showing a picture display unit, of which one part of the display panel is cut;</li><li><figref idref="f0003">FIG. 3</figref> is a block diagram of a high-frequency sputtering apparatus arranging a target for use with the present invention, i.e. which can be used for imparting an antistatic film to a spacer substrate;</li><li><figref idref="f0004">FIG. 4</figref> is a figure showing a relation between the resistivity of a Pt-Al mixture-nitride film and the total pressure of a sputtering gas;</li><li><figref idref="f0004">FIG. 5</figref> is a figure showing a relation between the resistivity of a Pt-AlN mixture-nitride film and the total pressure of a sputtering gas;</li><li><figref idref="f0005">FIG. 6</figref> is a figure showing the variation of the resistivity of a Pt-Al mixture-nitride film;</li><li><figref idref="f0006">FIG. 7</figref> is a cross-sectional schematic view of an image-forming apparatus using an electron-emitting device, for describing the mechanism of an electrostatic charge in a spacer; and</li><li><figref idref="f0006">FIG. 8</figref> is a view explaining the deviation of an electron beam ΔL which appears as the disarray of a display image due to the influence of a spacer</li></ul>

0019The present invention provides a method for manufacturing an antistatic film containing aluminum and platinum, comprising sputtering the mixture target in an atmosphere containing nitrogen and oxygen, as defined in claim 1.

0020A target as used according to the present invention is used as a target of a sputtering apparatus. This target can produce a resistive film having high reproducibility, superior controllability of a resistivity value, and temperature characteristics of the resistance.

0021In addition, the method for manufacturing an antistatic film according to the present invention has the effect comprising the variation of the resistivity less and the reproducibility of the film characteristic (resistivity) higher than those with binary simultaneous sputtering.

(Embodiments)

0022First of all, an antistatic film which can be manufactured according to the present invention is a resistive film as shown in <figref idref="f0001">FIG. 1</figref> that is a schematic view showing the cross-sectional shape observed with a TEM (a transmission electron microscope), having a structure comprising a plurality of particles 1 with an average particle diameter of 0.5 to 10 nm dispersed in a medium 2. Here, the average particle diameter is obtained by measuring the diameters of 20 particles in a cross-sectional shape as shown in <figref idref="f0001">FIG. 1</figref> and calculating the average.

0023If the particles have an average particle diameter of 0.5 nm or larger, preferably 1 nm or larger, a resistive film including them can be judged to have adequate temperature characteristics of resistance. Specifically, the resistive film can be judged to have little variation of resistance due to a temperature change. Accordingly, when the spacer having the resistive film as an antistatic film is used in a picture display unit, the spacer can reduce the disarray of a display image caused by it. In addition, the above described average particle diameter is 10 nm or smaller, and preferably 9 nm or smaller from the viewpoint comprising a resistivity of the resistive film equal to or higher than 1×10⁶ Ωm.

0024The above described antistatic film can be used for a spacer with an electron source which is arranged in an airtight vessel having temperature change for preventing electrostatic charge in the airtight vessel.

0025Embodiments according to the present invention will now be described below.

0026In an embodiment an antistatic film is manufactured according to claim 1, which has a structure comprising a plurality of conductor particles with particle diameters of 0.5 to 10 nm dispersed in a medium containing a nitride and an oxide.

0027The conductor is platinum from the viewpoint of stability and controllability for a resistivity value. In addition, the above described medium containing a nitride and an oxide is aluminum nitride/oxide from the viewpoint of stability and controllability for a resistivity value, and the adequate temperature characteristics of resistance.

0028In addition, when the antistatic film manufactured in the above described embodiment is applied on the surface of a spacer arranged between first and second substrates particularly of a picture display unit provided with an airtight vessel having the first substrate with an electron source arranged thereon and the second substrate with an image display member arranged so as to face the above described electron source, among electron-generating devices, the above each resistive film has the resistivity preferably of ρ = 1×10⁴ to 1×10¹¹ Ωcm, and has a conductor content preferably of 0.1 to 10 atomic%.

0029Subsequently, a method for obtaining the above described resistive film will be described.

0030The above described resistive film is preferably formed (1) with a sputtering technique by using a mixture target containing at least a component composing a platinum conductor particle as described above and an aluminum component to be nitrided and oxidized for composing an aluminum nitride and oxide, and (2) in a sputtering atmosphere represented by a mixed gas atmosphere of nitrogen mixed with oxygen, wherein the partial pressure of nitrogen and oxygen is controlled to 70% or more in total.

0031The particle diameter can be appropriately varied in the range of 0.5 to 10 nm by changing the component and the ratio in the composition of a mixing target, and a gas sort, a sputtering pressure and an electrification power during film formation by sputtering, in the above described conditions (1) and (2), so that a resistive film can be obtained so as to acquire the resistance controlled to a preferable range for an electron generating device to which the resistive film is applied.

0032Subsequently, a sputtering apparatus used for forming the resistive film according to the above described embodiments will be described.

(Sputtering apparatus)

0033<figref idref="f0003">FIG. 3</figref> shows the configuration of a high-frequency sputtering apparatus used in the present embodiment.

0034The summary of the process of forming the above described resistive film by using it will be now described. At first, a substrate 201 is put on a film-forming tray 202, and is charged into a preliminary exhaust hood 203. The preliminary exhaust hood is exhausted to a vacuum degree of 5×10^-4 [Pa] or lower with a vacuum pump 204, and then the film-forming tray 202 is moved to a film-forming chamber 206 by a conveyance roller 205. Then, the film-forming chamber 206 is evacuated to a vacuum of 2×10^-5 [Pa] or less. After the vacuum has been confirmed to have reached the above described value, the specified quantity of a nitrogen gas, an oxygen gas, the mixed gas of argon and nitrogen, the mixed gas of argon and oxygen, or the mixed gas of nitrogen and oxygen is passed into the film-forming chamber through a gas introduction pipe 207. An orifice (not shown) is adjusted so that the total pressure of a sputtering gas becomes a predetermined pressure. After an atmosphere (the total pressure of a sputtering gas, a gas flow rate) has become stable, a predetermined power is applied to a high-frequency power source 208. In order to form a resistive film all over the surface of a substrate 201, a film-forming tray 202 is transported by a transporting roller 205 at the rate of 5 mm/min in the direction of an arrow in the drawing so as to cross directly under a mixture target 209, after sputtering discharge has started. The distance between the substrate and the mixture target is set to 200 mm.

0035Here, the high voltage of direct current applied to the mixture target 209 is adjusted by a high-frequency power source 208 so that the variation originating from the transportation of the substrate can be reduced.

0036The direction of transporting the substrate is not limited to one direction, but one-return transportation or a plurality of return transportation is acceptable. In addition, in some configurations of the apparatus, a film may be formed on the whole surface by rotating the substrate directly under the target.

0037Through the above described steps, a resistive film can be formed on a substrate.

0038In addition, when a resistive film is to be formed on both sides of a substrate, the film is formed on a surface (a first surface), then a film-forming tray 202 is returned to a preliminary exhaust hood 203, and the substrate 201 is taken out. Subsequently, the substrate 201 is reversed, and the above described resistive film is formed on a back surface (a second surface) similarly to the top surface (the first surface).

0039The resistive film to be formed on each surface of the top surface (a first surface) and the back surface (a second surface) may be a single-layered film with a desired film thickness, or a multilayer film consisting of a plurality of layers, which is produced by using a plurality of targets each having a different composition concentration ratio of the mixture from others.

0040Subsequently, a mixture target used in the above described sputtering apparatus will be described.

(Method for producing mixture target)

0041Here, a method for producing the above described mixture-sintered target will be described.

1) Mixing

0042At first, the weight of each powder of the above described components is measured in accordance with various composition concentration ratios, and the powders are mixed. For instance, the powders of Pt and Al, or Pt and AlN are mixed. A mixing device is not limited in particular, but a ball mill may be used. The powders are mixed in a non-oxidative atmosphere of nitrogen gas, Ar gas or the like. After the powders have been mixed, they may be classified by a sieve or the like as needed.

2) Calcination

0043The mixed powder is calcined in an inert atmosphere of nitrogen gas, Ar gas or the like, or in a vacuum. Alternatively, it may be calcined in a reducing atmosphere of hydrogen or the like. The mixed powder is preferably heated to 800 to 1,500°C, for calcination.

3) Pulverization

0044Thus formed solid material is pulverized. A pulverizing device is not limited in particular, but a ball mill may be used. The solid material is pulverized in a non-oxidative atmosphere of nitrogen gas, Ar gas or the like. After the solid material has been pulverized, the product may be classified with a sieve or the like as needed.

4) Baking

0045The mixed powder obtained through pulverization is pressure-baked in an inert atmosphere of nitrogen gas, Ar gas or the like, or in a vacuum, and a sintered compact is thereby obtained. The mixed powder may be pressure-baked in a reducing gas atmosphere of hydrogen or the like. Hot pressing is preferably used for pressure baking. The sintered compact is formed so as to have a predetermined plate thickness and shape for being sputtered, then is preferably heated to 800 to 1,500°C under the pressure of 1 to 2 MPa, which is a baking step, and becomes a mixture-sintered target.

(Method for producing mixture-melted alloy target)

0046Here, a method for producing a mixture-melted alloy target will be described.

1) Melting

0047At first, the weight of each raw material of the above described components is measured in accordance with various composition concentration ratios, and the raw materials are mixed. For instance, the raw materials of Pt and Al, or Pt and AlN are mixed, and melt in a melting furnace. A melting method for the raw materials is not limited in particular, but in order to prevent the contamination of atmospheric impurities, the raw materials are desirably melt in a vacuum.

2) Cooling

0048The above described melted mixture is cooled while the condition is adjusted not so as to cause the segregation of components.

3) Forge-rolling

0049Thus produced solid material is forge-rolled while being heated. A void (a cavity) produced during cooling is filled, and melting irregularity and density irregularity are uniformized.

4) Baking

0050The solid material obtained through the above described steps is pressure-baked in an inert atmosphere of Ar gas or the like, or in a vacuum, and a Pt-Al or Pt-AlN mixture-melting alloy is thereby obtained. The solid material may be pressure-baked in a reducing gas atmosphere of hydrogen or the like. Hot pressing is preferably used for pressure baking. The mixture-melting alloy is formed so as to have a predetermined plate thickness and shape for being, sputtered, and becomes a mixture-melted alloy target.

0051In the same way as described above, an aluminum-platinum mixture target containing 95 wt.% or more aluminum and platinum, or an aluminum nitride -platinum mixture target containing 95 wt.% or more aluminum and platinum can be formed.

0052In the next place, the whole configuration of a picture display unit will be described, in which a substrate having the above described resistive film formed thereon as a spacer, and the spacer is inserted into the picture display unit.

(Panel configuration)

0053<figref idref="f0002">FIG. 2</figref> is a perspective view of a display panel in a picture display unit, in which one part of the panel is cut in order to show an inner structure.

0054In the figure, reference numeral 915 denotes a rear plate, reference numeral 916 a side wall, and reference numeral 917 a face plate. The rear plate 915, the side wall 916 and the face plate 917 forms an airtight vessel for keeping the inside of the display panel into a vacuum. When the airtight vessel is assembled, joining areas between members need to be sealed in order to make the joining areas retain adequate strength and airtightness. The sealing is achieved, for example, by applying frit glass to the joining areas and baking it at 400 to 500°C for 10 minutes or longer in atmospheric air or a nitrogenous atmosphere. A method for evacuating the inside of an airtight vessel to a vacuum will be described later.

0055In addition, the inside of the above described airtight vessel is kept in a vacuum of about 10^-4 [Pa], so that for the purpose of preventing the destruction of the airtight vessel due to an ambient pressure or unexpected shock, a spacer 920 is provided so as to make the airtight vessel an ambient-pressure resistant structure. As the spacer, a substrate having an antistatic film is used, which is produced by using the above described mixture targets having various composition concentration ratios in forming films.

0056A substrate 911 is fixed on a rear plate 915, while having N×M pieces of surface conduction electron-emitting devices 912 formed thereon. Here, N and M are positive integers of 2 or more and are appropriately set in accordance with an objective display pixel number. For instance, in a display device for displaying a high definition picture, those numbers are preferably N = 3,000 and M = 1,000 or more. In the present embodiment, the numbers are set to N = 3,072 and M = 1,024.

0057The above described N×M pieces of surface conduction electron-emitting devices are simple-matrix-wired by M lines of row-directional wiring 913 and N lines of column-directional wiring 914. The part composed by the substrate 911, the surface conduction electron-emitting devices 912, the row-directional wiring 913 and the column-directional wiring 914 is called an electron source substrate.

0058In addition, a fluorescent screen 918 is formed on the undersurface of a faceplate 917. In addition, a metal back 919, which is well known in the field of CRT, is arranged on the surface of the rear plate side of the fluorescent screen 918.

0059Dx1 to Dxm, Dy1 to Dyn and Hv are terminals for electric connection having an airtight structure, which is arranged for electrically connecting the display panel to a not-shown electric circuit.

0060Terminals Dx1 to Dxm are electrically connected to the row-directional wiring 913 of the surface conduction electron-emitting devices, terminals Dy1 to Dyn to the column-directional wiring 914 of the surface conduction electron-emitting devices, and Hv to a metal back (a metallic membrane) of a face plate 919.

0061In order to evacuate the inside of an airtight vessel to a vacuum, the airtight vessel is assembled, a not-shown exhaust pipe is connected with a vacuum pump, and the inside of the airtight vessel is evacuated to a vacuum of 10^-5 [Pa] or lower. Afterwards, the exhaust pipe is sealed. Then, in order to keep the vacuum in the airtight vessel, a getter film (not shown) is formed just before or after sealing, on a predetermined position in the airtight vessel. The getter film is formed by heating and evaporating a getter material containing, for instance, Ba as a main component with a heater or high-frequency heating, and by the adsorption effect of the getter film, the inside of the airtight vessel is kept to a vacuum of 1×10^-3 to 1×10^-5 [Pa].

0062In the above described picture display unit using a display panel, when electric voltage is applied to each surface conduction electron-emitting device 912 through terminals outside a vessel, Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from each surface conduction electron-emitting device 912. Concurrently with it, a high pressure of several hundreds [V] to several thousands [V] is applied to a metal back (metal membrane) 919 through the terminals outside the vessel Hv to accelerate the above described emitted electrons and make them collide with the inner surface of a face plate 917. Thereby, each phosphor of each color composing a phosphor layer 918 is activated to emit light, and images are displayed.

0063Normally, voltage applied to the surface conduction electron-emitting device 912 according to the present invention is around 12 to 16 [V], a distance d between a metal back (a metal membrane) 919 and the surface conduction electron-emitting device 912 is around 0.1 to 8 [mm], and voltage between the metal back (the metal membrane) 919 and the surface conduction electron-emitting device 912 is about 0.1 [kV] to 12 [kV].

0064A picture display unit and a spacer having a resistance film (an antistatic film) formed on the surface, which is used as a support structure therein, have been described above. However, the spacer can be used not only for the picture display unit, but also as a light-emitting source substituted for a light-emitting diode of an optical printer constituted by a photosensitive drum and a light-emitting diode. In addition, if, at this time, the above described m lines of row-directional wiring and the n lines of column-directional wiring are appropriately selected, the spacer can be applied to not only a line-shaped light-emitting source but also a two-dimensional light-emitting source. In the above case, a usable body to be irradiated with electron can be not only a material directly emitting light such as a phosphor, but also a member on which a latent image is formed by the electrostatic charge of electrons. In addition, the above described antistatic film can be applied to an electron-generating device, even when a material other than an image-forming member such as a phosphor is used as a body to be irradiated with the electrons emitted from an electron source, like in an electron microscope.

(Evaluation method for image)

0065A spacer substrate was prepared by forming an antistatic film according to the present invention on a glass substrate, and using the same as a spacer in a picture display unit using the surface conduction electron-emitting device.

0066When the diselectrification capability of the spacer 801 is insufficient, as shown in <figref idref="f0006">FIG. 8</figref>, the trajectory of a beam is disturbed and the position of the lighting pixel which should be displayed at regular intervals moves. When a distance L between the original positions 802 of beams is defined as 1L, the deviation of a difference between the original position and the position 803 of a beam moved by a spacer is shown in ΔL.

0067The evaluation was carried out by placing a display device in an adequately bright room, and making the 50 subjects of adult men and women visually observe a display image at a place 1m apart from the panel face.

0068The observation result for the disarray of a display image due to the deviation of an electron beam was divided into 3 evaluation stages of "invisible" "visible but not annoying" and "visible and annoying", and a relationship between the stage and the deviation of the beam ΔL was determined. When the majority of the subjects answered "invisible", the deviation ΔL was 0 - 0.01L; when they answered "visible but not annoying", the deviation ΔL was 0.01 - 0.03L; and when they answered 3 "visible and annoying", the deviation ΔL was 0.03L or more. The result is shown in Table 1.

0069The performance of an antistatic film which can be manufactured according to the present invention was evaluated by installing a spacer provided with the resistive film in a display device, and measuring the deviation of an electron beam ΔL in an image affected by the spacer. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="38mm" /><colspec colnum="2" colname="col2" colwidth="47mm" /><colspec colnum="3" colname="col3" colwidth="47mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><thead><row><entry align="center" valign="top">Visual evaluation</entry><entry align="center" valign="top">Deviation of electron beam ΔL</entry><entry align="center" valign="top">Deviation of electron beam [%]</entry><entry align="center" valign="top">Evaluation</entry></row></thead><tbody><row><entry align="center">Invisible</entry><entry align="center">0 - 0.01 L</entry><entry align="center">0-1%</entry><entry align="center">⊚</entry></row><row><entry align="center">Visible but not annoying</entry><entry align="center">0.01 - 0.03 L</entry><entry align="center">1-3%</entry><entry align="center">○</entry></row><row><entry align="center">Visible and annoying</entry><entry align="center">0.03L or more</entry><entry align="center">3% or more</entry><entry align="center">×</entry></row></tbody></tgroup></table></tables>

Examples

0070Specific examples according to the present invention [(Examples 24-27) as well as explanatory examples (Examples 1-23 and 28, Comparative Examples 1 and 2)] will be described below. Here, atomic% indicates the proportion of the number of atoms of monoatoms, and a Pt/Al weight ratio is calculated by (atomic% of Pt × atomic weight of Pt)/(atomic% of Al × atomic weight of Al).

(Example 1)

Pt = 5 atomic% Pt-Al-melted alloy

0071The raw materials of Pt and Al were weighed out so as to have the composition ratio of 5 atomic% Pt to 95 atomic% Al, and then were mixed. The mixed materials were melted in a vacuum melting furnace to produce an alloy. The alloy was cooled, and then was forge-rolled to further uniformize the component distribution. The melted alloy was pressure-baked in a vacuum, and was molded so as to acquire a predetermined plate thickness and shape suitable for a sputtering target, and the product became a Pt-Al-melted alloy mixture target. The density of the Pt-Al-melted alloy was 3.6 g/cm³.

0072A Pt-Al-melted alloy was installed as the target of a high-frequency sputtering apparatus shown in <figref idref="f0003">FIG. 3</figref>, the flow rate of N₂ was set to 100 sccm, and a Pt-Al mixture-nitrided film was formed with varied total pressures. The obtained Pt-Al mixture-nitrided film had the resistivity shown in <figref idref="f0004">FIG. 4</figref>.

0073Thus produced Pt-Al mixture-nitrided film was analyzed with the use of an RBS (Rutherford backscattering Spectrometory) method, and had the composition shown in Table 2. In addition, the density of the Pt-Al mixture-nitrided film was 3.5 g/cm³. <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="18mm" /><colspec colnum="2" colname="col2" colwidth="34mm" /><colspec colnum="3" colname="col3" colwidth="21mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="21mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="33mm" /><thead><row valign="middle"><entry morerows="1" align="center">Film type</entry><entry morerows="1" align="center">Pt content (atomic%)</entry><entry namest="col3" nameend="col6" align="center">Concentration measured with RBS analysis (atomic%)</entry><entry morerows="1" align="center">Film density (g/cm³)</entry></row><row><entry align="center" valign="top">N</entry><entry align="center" valign="top">O</entry><entry align="center" valign="top">Al</entry><entry align="center" valign="top">Pt</entry></row></thead><tbody><row rowsep="0"><entry align="center">Pt-Al-N</entry><entry align="center">Pt = 3</entry><entry align="char" char=".">49.8</entry><entry align="char" char="." charoff="10">0.3</entry><entry align="char" char="." charoff="18">49.1</entry><entry align="char" char="." charoff="10">0.8</entry><entry align="char" char="." charoff="6">3.0</entry></row><row><entry align="center" /><entry align="center">Pt = 5</entry><entry align="char" char=".">50.0</entry><entry align="char" char="." charoff="10">0.4</entry><entry align="char" char="." charoff="18">47.1</entry><entry align="char" char="." charoff="10">2.5</entry><entry align="char" char="." charoff="6">3.5</entry></row></tbody></tgroup></table></tables>

(Example 2)

0074Pt = 3 atomic% Pt-Al-melted alloy

0075Similarly to the Example 1, raw materials were weighed out so as to have the composition ratio of 3 atomic% Pt to 97 atomic% Al, then, were mixed, melted, cooled, forge-rolled and pressure-baked. Thus, a Pt-Al-melted alloy mixture target was obtained. The density of the Pt-Al-melted alloy was 3.2 g/cm³.

0076Similarly to the Example 1, a Pt-Al mixture-nitrided film was formed, and had resistivity shown in <figref idref="f0004">FIG. 4</figref>.

0077Thus produced Pt-Al mixture-nitrided film was analyzed with the use of an RBS (Rutherford backscattering Spectrometory) method, and had a composition shown in Table 1. In addition, the density of the Pt-Al mixture-nitrided film was 3.0 g/cm³.

(Example 3)

0078Pt = 5 atomic% Pt-AlN sintered compact

0079Instead of metallic aluminum, aluminum nitride was used as a raw material.

0080The powders of Pt and AlN were weighed out so as to have the composition ratio of 5 atomic% Pt to 95 atomic% AlN, and then were mixed. The powders were mixed with a ball mill in a non-oxidization atmosphere of nitrogen gas. After having been mixed, the powders were classified with a sieve to acquire a further uniformized granular form. Thus mixed powder was calcined in a vacuum.

0081Thus formed solid material was pulverized with the use of a ball mill in the non-oxidation atmosphere of nitrogen gas. After having been pulverized, the powders were classified with a sieve to acquire a further uniformized granular form.

0082The mixed powder obtained through pulverization was pressure-baked in a vacuum to provide a sintered compact. For the pressure-baking, a hot pressing process of heating the mixed powder to 1,500°C at the pressure of 2 MPa was employed. The sintered compact was formed so as to acquire a predetermined plate thickness and shape suitable for a sputtering target, and thus a Pt-AlN mixture sintered target was obtained. The Pt-AlN sintered compact had the density of 2.4 g/cm³.

0083Similarly to the Example 1, the N₂ flow rate was set to 100 sccm, and a Pt-AlN mixture-nitrided film was formed with varied total pressures. Then, the obtained film had resistivity shown in <figref idref="f0004">FIG. 5</figref>.

0084Thus produced Pt-AlN mixture-nitrided film was analyzed with the use of an RBS (Rutherford backscattering Spectrometory) method, and was proved to have the composition shown in Table 3. In addition, the Pt-AlN mixture-nitrided film had the density of 3.2 g/cm³. <tables id="tabl0003" num="0003"><table frame="all"><title>Table 3</title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="18mm" /><colspec colnum="2" colname="col2" colwidth="34mm" /><colspec colnum="3" colname="col3" colwidth="21mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="21mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="33mm" /><thead><row valign="middle"><entry morerows="1" align="center">Film type</entry><entry morerows="1" align="center">Pt content (atomic%)</entry><entry namest="col3" nameend="col6" align="center">Concentration measured with RBS analysis (atomic%)</entry><entry morerows="1" align="center">Film density (g/cm³)</entry></row><row><entry align="center" valign="top">N</entry><entry align="center" valign="top">O</entry><entry align="center" valign="top">Al</entry><entry align="center" valign="top">Pt</entry></row></thead><tbody><row rowsep="0"><entry align="center">Pt-Al-N</entry><entry align="center">Pt = 3</entry><entry align="char" char=".">45.6</entry><entry align="char" char="." charoff="10">8.5</entry><entry align="char" char="." charoff="18">45.0</entry><entry align="char" char="." charoff="10">0.9</entry><entry align="char" char="." charoff="6">2.8</entry></row><row><entry align="center" /><entry align="center">Pt = 5</entry><entry align="char" char=".">45.7</entry><entry align="char" char="." charoff="10">9.0</entry><entry align="char" char="." charoff="18">43.0</entry><entry align="char" char="." charoff="10">2.3</entry><entry align="char" char="." charoff="6">3.2</entry></row></tbody></tgroup></table></tables>

(Example 4)

0085Pt = 3 atomic% Pt-AlN sintered compact

0086Similarly to the Example 3, instead of metallic aluminum, aluminum nitride was used as a raw material, and the raw materials were weighed out so as to have the composition ratio of 3 atomic% Pt to 97 atomic% AlN, then, were mixed, calcinated, pulverized, and pressure-baked. Thus, a Pt-AlN mixture sintered target was obtained. The Pt-AlN sintered compact had the density of 2.0 g/cm³.

0087Similarly to the Example 1, a N₂ flow rate was set to 100 sccm, and a Pt-AlN mixture-nitrided film was formed with varied total pressures. Then, the obtained film had resistivity shown in <figref idref="f0004">FIG. 5</figref>.

0088Thus produced Pt-AlN mixture-nitrided film was analyzed with the use of an RBS (Rutherford backscattering) method, and was proved to have the composition shown in Table 3. In addition, the Pt-AlN mixture-nitrided film had the density of 2.8 g/cm³.

(Comparative Example 1)

Comparison with binary target: Pt = 5 atomic% nitrided film

0089The targets made of elemental Pt and elemental Al were separately prepared. Similarly to the Example 1, a Pt target and an Al target were each installed as the target of a high-frequency sputtering apparatus. Under the conditions of the total pressure of 0.2 Pa and the N₂ flow rate of 100 sccm, the power for electrifying each target was adjusted. The film was formed so as to acquire the same Pt content (Pt = 2.5 atomic%) as the formed film with the use of the Pt = 5 atomic% Pt-Al target.

0090The films were repeatedly formed under thus adjusted equal conditions, but the produced Pt-Al mixture-nitrided film had varied resistivities as are shown in <figref idref="f0005">FIG. 6</figref>.

(Comparative Example 2)

Comparison with binary target: Pt = 3 atomic% nitrided film

0091The targets made of elemental Pt and elemental Al were separately prepared. Similarly to the Example 1, a Pt target and an Al target were each installed as the target of a high-frequency sputtering apparatus. Under the conditions of the total pressure of 0.2 Pa and the N₂ flow rate of 100 sccm, the power for electrifying each target was adjusted. The conditions were adjusted so that the film could acquire the same Pt content (Pt = 0.8 atomic%) as the formed film with the use of a Pt = 3 atomic% Pt-Al target.

0092The films were repeatedly formed under thus adjusted equal conditions, but the produced Pt-Al mixture-nitrided film had the variation of resistivities as shown in <figref idref="f0005">FIG. 6</figref>.

(Example 5)

0093As a target used for a high-frequency sputtering apparatus shown in <figref idref="f0002">FIG. 2</figref>, a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al and the diameter of 8 inches produced in the manner of Example 1 was installed. Under the nitrogen/argon mixed gas flow rate of N₂ = 70 sccm and Ar = 30 sccm and the sputtering pressure of 1.0 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0094A glass substrate was introduced into a film-forming chamber, and a film was formed on it. Sputtering time was 30 minutes. Thus obtained resistive film had the film thickness of 200 nm, and the resistivity of 2×10⁹ Ωcm.

0095Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM ( transmission electron microscope), and showed the diameter of 0.4 nm.

(Example 6)

0096A Pt-Al mixture target was set which had the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. Under the nitrogen/argon mixed gas flow rate of N₂=70 sccm and Ar=30 sccm and the sputtering pressure of 0.5 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0097A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 25 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁹ Ωcm.

0098Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 0.5 nm.

(Example 7)

0099A Pt-Al mixture target was set which had the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. Under the nitrogen/argon mixed gas flow rate of N₂=70 sccm and Ar=30 sccm and the sputtering pressure of 0.3 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0100A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 20 minutes, a resistive film having the thickness of 200 nm was obtained.

0101The obtained resistive film had the resistivity of 8×10⁸ Ωcm.

0102Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 0.6 nm.

(Example 8)

0103A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the nitrogen/argon mixed gas flow rate of N₂=70 sccm and Ar=30 sccm and the sputtering pressure of 1.0 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0104A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 30 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁴ Ωcm.

0105Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 9 nm.

(Example 9)

0106A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the nitrogen/argon mixed gas flow rate of N₂=70 sccm and Ar=30 sccm and the sputtering pressure of 0.5 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0107A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 25 minutes, a resistive film having the thickness of 200 nm was obtained.

0108The obtained resistive film had the resistivity of 1×10⁴ Ωcm.

0109Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminium nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 10 nm.

(Example 10)

0110A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the nitrogen/argon mixed gas flow rate of N₂ = 70 sccm and Ar = 30 sccm and the sputtering pressure of 0.3 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0111A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 20 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1x10³ Ωcm.

0112Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminium nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 11 nm.

(Example 11)

0113A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 1.0 Pa, and an electrification power to 2,400 W.

0114After the sputtering time of 70 minutes, a resistive film having the thickness of 200 nm was obtained. The resistive film had the resistivity of 1×10¹¹ Ωcm.

0115Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 0.8 nm.

(Example 12)

0116A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 0.5 Pa, and an electrification power to 2,400 W.

0117After the sputtering time of 65 minutes, a resistive film having the film thickness of 200 nm was obtained. The resistive film had the resistivity of 1×10¹¹ Ωcm.

0118Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 1 nm.

(Example 13)

0119A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 0.3 Pa, and an electrification power to 2,400 W.

0120After the sputtering time of 60 minutes, a resistive film having the film thickness of 200 nm was obtained. The resistive film had the resistivity of 8×10¹⁰ Ωcm.

0121Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the diameter of 2 nm.

(Example 14)

0122A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 1.0 Pa, and an electrification power to 2,400 W.

0123After the sputtering time of 70 minutes, a resistive film having the thickness of 200 nm was obtained. The resistive film had the resistivity of 1×10⁴ Ωcm.

0124Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 9 nm.

(Example 15)

0125A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 0.5 Pa, and an electrification power to 2,400 W.

0126After the sputtering time of 65 minutes, a resistive film having the film thickness of 200 nm was obtained. The resistive film had the resistivity of 1×10⁴ Ωcm.

0127Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 10 nm.

(Example 16)

0128A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al and the diameter of 8 inches, at the nitrogen-gas flow rate of N₂=100 sccm. A sputtering pressure was set to 0.3 Pa, and an electrification power to 2,400 W.

0129After the sputtering time of 60 minutes, a resistive film having the film thickness of 200 nm was obtained. The resistive film had the resistivity of 1×10² Ωcm.

0130Thus produced Pt-Al mixture-nitrided film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride through a TEM (transmission electron microscope), and showed the average particle diameter of 11 nm.

(Example 17)

0131A Pt-Al mixture target was set which had the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 1.0 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0132A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 70 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 5×10¹¹ Ωcm.

0133Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.4 nm.

(Example 18)

0134A Pt-Al mixture target was set which had the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 0.5 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0135A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 65 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10¹¹ Ωcm.

0136Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.5 nm.

(Example 19)

0137A Pt-Al mixture target was set which had the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 0.3 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0138A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 60 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10¹¹ Ωcm.

0139Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.6 nm.

(Example 20)

0140A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 1.0 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0141A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 70 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁸ Ωcm.

0142Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the diameter of 8 nm.

(Example 21)

0143A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 0.5 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0144A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 65 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁷ Ωcm.

0145Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 9 nm.

(Example 22)

0146A Pt-Al mixture target was set which had the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. Under the oxygen gas flow rate of O₂=100 sccm and the sputtering pressure of 0.3 Pa, the above described Pt-Al mixture target was sputtered with the high-frequency electrification power of 2,400 W.

0147A glass substrate was introduced into a film-forming chamber, and the film was formed on it. After the sputtering time of 60 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁶ Ωcm.

0148Thus produced Pt-Al mixture-oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 10 nm.

(Example 23)

0149A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 1.0 Pa, and an electrification power to 2,400 W.

0150After the sputtering time of 35 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 2×10¹² Ωcm.

0151Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.4 nm.

(Example 24)

0152A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 0.5 Pa, and an electrification power to 2,400 W.

0153After the sputtering time of 30 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10¹¹ Ωcm.

0154Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.5 nm.

(Example 25)

0155A film was formed with the use of a Pt-Al mixture target having the composition ratio of 2 atomic% Pt to 98 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 0.3 Pa, and an electrification power to 2,400 W.

0156The sputtering time was 25 minutes. Then, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10¹¹ Ωcm.

0157Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 0.6 nm.

(Example 26)

0158A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 1.0 Pa, and an electrification power to 2,400 W.

0159After the sputtering time of 35 minutes, a resistive film having the film thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁵ Ωcm.

0160Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 9 nm.

(Example 27)

0161A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 0.5 Pa, and an electrification power to 2,400 W.

0162After the sputtering time of 30 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 1×10⁴ Ωcm.

0163Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 10 nm.

(Example 28)

0164A film was formed with the use of a Pt-Al mixture target having the composition ratio of 30 atomic% Pt to 70 atomic% Al, and the diameter of 8 inches. The film was formed at the oxygen/nitrogen mixed gas flow rate of O₂=2 sccm and N₂=98 sccm. A sputtering pressure was set to 0.3 Pa, and an electrification power to 2,400 W.

0165After the sputtering time of 25 minutes, a resistive film having the thickness of 200 nm was obtained. The obtained resistive film had the resistivity of 5×10³ Ωcm.

0166Thus produced Pt-Al mixture-nitrided/oxidized film was subjected to the measurement of the average particle diameter of platinum particles dispersed in the medium of aluminum nitride and aluminum oxide through a TEM (transmission electron microscope), and showed the average particle diameter of 11 nm.

0167A spacer substrate was prepared by forming each resistive film shown in the above described Examples 5 to 28 as an antistatic film on a glass substrate, and was used as a spacer in a picture display unit using the surface conduction electron-emitting device. The influence of the spacer on an image was evaluated by measuring the deviation of an electron beam ΔL.

0168A spacer provided with a resistive film having a resistivity p of 1×10⁴ to 1×10¹¹ Ωcm and containing platinum particles with diameters in a range of 0.5 to 10 nm, showed the deviation of an electron beam ΔL of 3% or less (0.03L or less) and an adequate display image.

0169A spacer provided with a resistive film having a resistivity ρ of 1×10⁴ to 1×10¹¹ Ωcm and containing platinum particles with diameters in a range of 1 to 9 nm, showed the deviation of an electron beam ΔL of 1% or less (0.01L or less) and a particularly adequate display image.

0170The results are shown in Table 4. <tables id="tabl0004" num="0004"><table frame="all"><title>Table 4</title><tgroup cols="8"><colspec colnum="1" colname="col1" colwidth="21mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><colspec colnum="3" colname="col3" colwidth="22mm" /><colspec colnum="4" colname="col4" colwidth="17mm" /><colspec colnum="5" colname="col5" colwidth="22mm" /><colspec colnum="6" colname="col6" colwidth="21mm" /><colspec colnum="7" colname="col7" colwidth="23mm" /><colspec colnum="8" colname="col8" colwidth="23mm" /><thead><row><entry valign="middle" /><entry align="center" valign="middle">Film type</entry><entry align="center" valign="middle">TGT composition</entry><entry align="center" valign="middle">Gas type</entry><entry align="center" valign="middle">Sputtering pressure [Pa]</entry><entry align="center" valign="middle">Resistivity [Ωcm]</entry><entry align="center" valign="middle">Average particle diameter [nm]</entry><entry align="center" valign="middle">Image evaluation</entry></row></thead><tbody><row><entry valign="middle">Example 5</entry><entry morerows="5" align="center" valign="middle">Pt-Al-N</entry><entry morerows="2" align="center" valign="middle">Pt:2% Al:98%</entry><entry morerows="5" align="center" valign="middle">N₂/Ar</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">2.E+09</entry><entry align="center" valign="middle">0.4</entry><entry align="center" valign="middle">×</entry></row><row><entry valign="middle">Example 6</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+09</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 7</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">8.E+08</entry><entry align="center" valign="middle">0.6</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 8</entry><entry morerows="2" align="center" valign="middle">Pt:30% Al:70%</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">1.E+04</entry><entry align="center" valign="middle">9</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 9</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+04</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 10</entry><entry align="center" valign="middle">0.3 a</entry><entry align="center" valign="middle">1.E+03</entry><entry align="center" valign="middle">11</entry><entry align="center" valign="middle">×</entry></row><row><entry valign="middle">Example 11</entry><entry morerows="5" align="center" valign="middle">Pt-Al-N</entry><entry morerows="3" align="center" valign="middle">Pt2% Al:98%</entry><entry morerows="5" align="center" valign="middle">N₂</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">0.8</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 12</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">1</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 13</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">8.E+10</entry><entry align="center" valign="middle">2</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 14</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">1.E+04</entry><entry align="center" valign="middle">9</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 15</entry><entry morerows="1" align="center" valign="middle">Pt:30% Al:70%</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+04</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 16</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">1.E+02</entry><entry align="center" valign="middle">11</entry><entry align="center" valign="middle">×</entry></row><row><entry valign="middle">Example 17</entry><entry morerows="5" align="center" valign="middle">Pt-Al-O</entry><entry morerows="2" align="center" valign="middle">Pt:2% Al:98%</entry><entry morerows="5" align="center" valign="middle">O₂</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">5.E+11</entry><entry align="center" valign="middle">0.4</entry><entry align="center" valign="middle">×</entry></row><row><entry valign="middle">Example 18</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 19</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">0.6</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 20</entry><entry morerows="2" align="center" valign="middle">Pt:30% Al:70%</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">1.E+08</entry><entry align="center" valign="middle">8</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 21</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+07</entry><entry align="center" valign="middle">9</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 22</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">1.E+06</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 23</entry><entry morerows="5" align="center" valign="middle">Pt-Al-N-O</entry><entry morerows="2" align="center" valign="middle">Pt:2% Al:98%</entry><entry morerows="5" align="center" valign="middle">N₂/O₂</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">2.E+12</entry><entry align="center" valign="middle">0.4</entry><entry align="center" valign="middle">×</entry></row><row><entry valign="middle">Example 24</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 25</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">1.E+11</entry><entry align="center" valign="middle">0.6</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 26</entry><entry morerows="2" align="center" valign="middle">Pt:30% Al:70%</entry><entry align="center" valign="middle">1.0 Pa</entry><entry align="center" valign="middle">1.E+05</entry><entry align="center" valign="middle">9</entry><entry align="center" valign="middle">⊚</entry></row><row><entry valign="middle">Example 27</entry><entry align="center" valign="middle">0.5 Pa</entry><entry align="center" valign="middle">1.E+04</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">○</entry></row><row><entry valign="middle">Example 28</entry><entry align="center" valign="middle">0.3 Pa</entry><entry align="center" valign="middle">5.E+03</entry><entry align="center" valign="middle">11</entry><entry align="center" valign="middle">×</entry></row></tbody></tgroup></table></tables>

0171As described above, with the present invention an antistatic film can be manufactured which is superior in controllability for a resistivity value, stability and reproducibility and has adequate temperature characteristics of resistance.

0172With such antistatic film a picture display unit can be formed having the effect of reducing the instability of a display image, which originates from a temperature distribution in an airtight vessel caused by a temperature difference between a pair of substrates that compose the airtight vessel, and having superior display performance.