Band melting type single crystal semiconductor layer forming device

[Detailed Description of the Invention]

[Industrial Application] In the present invention, many crystals or a noncrystalline semiconductor layer on an insulating layer is especially re-crystallized about a zone fusion type single crystal semiconductor layer forming device. Therefore, it is related with a zone fusion type single crystal semiconductor layer forming device which is a comparatively big area and can manufacture a quality single crystal layer.

[Description of the Prior Art] When the zone fusion type single crystal semiconductor layer forming device used conventionally is shown in Drawing 3 and explained, it is the mosquito o heat from a lower side about sample wafer 3 which 1 mentions below in a figure. The tabular lower heater consisting of the carbon etc. which were constituted so that it might Temperature rising, and 2 are a top heater of the shape of a straight line constituted so that the end might move by fine Fast toward The other end while heating and Temperature rising(ing) sample wafer 3 from the upper part similarly. Arrow 5 shows the move direction of top heater 2. Sample wafer 3 has fusion and a polycrystalline silicon layer which should be re-crystallized. As for this sample wafer 3, as shown in Drawing 4, about 0.5-micrometer thick silicon dioxide layer 7 is formed on a new vista of silicon substrate 6 of a single crystal, and fusion and polycrystalline silicon @8 which should be re-crystallized are 0.5microll18 on that field! It has the thickness which is a degree and is formed. On the field of polycrystalline silicon layer 8, Silicon dioxide layer of 2 micrometers and nitriding silicon layer 10 of about 3 Qnm laminate that this polycrystalline silicon layer exfoliates from silicon substrate 6 of a single crystal at the time of fusion as a protection layer for protecting, and it is formed. It Therefore, and in order to re-crystallize polycrystalline silicon @8 in sample wafer 3 and to make it a single crystal, sample wafer 3 is heated from a lower side to 1200 degreeC with lower heater 1. It Temperature rising. And for example, this top heater 2 is made to move to the certain direction shown by arrow 5 from the end of 1[Perilla frutescens (L.) Britton var. crispa (Thunb.) Decne. like 1~2m1N from the upper surface of sample wafer 3 at i1 degree of 2-m1ll/a second, and the whole region of sample wafer 3 is scanned in the bottom which Temperature rising(ed) top heater 2 to 2000 degreeC. At this time, fusion layer 4 according to the shape of top heater 2 will be made into sample wafer 3, and when this moves with movement of top heater 2, large crystal grain-ization of polycrystalline silicon layer 8 in sample wafer 3 will be attained. This growth is performed in inactive gas atmosphere, such as argon. Drawing 5 is a figure showing the zone fusion type single crystal semiconductor layer forming device which is another example of conventional technology. In the figure, this device has composition which replaced multiple lower heater 1. top heaters 2 of Drawing 3 of an outline with tubular lamp of book 11for MW heating a~11e, and tubular lamp 12 for fusion object formation, respectively. If it explains in detail common, sample wafer 3o of the same composition as Drawing 4 will be placed on wafer retainer board 14. Tubular lamp 12 for fusion object formation which has collection mirror 120 in parallel with this upper surface is formed in the upper part of sample wafer 30. Collection mirror 120 carries out the condensing irradiation of the light from tubular lamp 12 for fusion object formation at sample wafer 30, heats this, and fuses the polycrystalline silicon layer beltlike. The lower part of wafer retainer board 14 is provided with annular lamp 11a~11e for two or more substrate heating in parallel with the undersurface of this wafer retainer board. Each tubular lamp lla~11e for substrate heating has reflective mirror 110a~110e, respectively. The tube axis of each tubular lamp 11a~11e for substrate heating separates an equal interval the tube axis of tubular lamp 12 for fusion object formation, parallel, and mutually, and is arranged. The light from tubular lamp 11for a substrate heating a~11e from which each reflective mirror 110a~110e protects the Scatter i meeting of the light from each tubular lamp 11for substrate heating a~11e, respectively irradiates with all the undersurfaces of sea urchin A retainer board 14, and heats this, The silicon substrate of the single crystal of sample wafer 3o is heated by it. In this device, in order to heat uniformly the silicon substrate of the single crystal of sample wafer 3o, the number of the tubular lamp for 110 heat is made comparatively large. Sample sea urchin l\30 is moved in the arrow 15 direction to tubular lamp 12 for fusion object formation with tubular lamp 11a~11e for substrate heating, and that whole region is scanned, irradiating with sample wafer 30 with the light from this tubular lamp 12 for fusion object formation. At this time, the field fused beltlike is moved between 2 oxidization silicon 1 of those upper and lower sides, and it does in this way, and it is re-crystallized and the polycrystalline silicon layer of sample wafer 30 becomes a single crystal. Like Above, in order to heat the silicon substrate of a sample wafer uniformly, the device which restricted the number of the tubular lamp for substrate heating only to one was also provided.

The zone fusion type single crystal semiconductor layer forming device of the [Problem(s) to be Solved by the Invention] former is constituted as mentioned above, and the consideration which can make this uniform enough was made about heating of the silicon substrate of the single crystal of a sample wafer. However, since a sample wafer will be heated from the up-and-down both sides if the conventional device actually performs zone fusion, The phenomenon in which the fusion conditions of the central part and a circumference part differed that heat cannot escape from a sample wafer central part easily happened, and there was a problem that the sample wafer of 4 inches or more in diameter a large area could not be re-crystallized by the zone fusion by one-time scan however it may design. Also when it experiments in consideration of heating concentration so that a part of center of a sample wafer can be fused, missing the solidification latent heat at the time of resulting in a solid from fusion cannot be finished enough, and the phenomenon in which the temperature gradient in connection with crystal growth becomes loose, and does not serve as a field where a crystal growth side is perpendicular to the direction of movement of zone fusion happens. This phenomenon is explained still in detail with reference to Drawing 6 (A) and (B). Drawing 6 (A) is a sectional view of the sample wafer under zone fusion, and Drawing 6 (B) is Drawing 6 (it is a top view containing the polycrystalline silicon layer of A>.). In a figure, 80 is a beltlike fusion field by lamp light 13 of polycrystalline silicon layer 8, and 81 is the single-crystal-ized silicon layer. If the concentration gradient in connection with crystal growth becomes loose, crystal growth side 16 will turn into a <111> side, and will become like a serration. For this reason, the increase in 1 Analysis of impurities or stress arose at a place like 17, although it was a small inclination, crystal grain community 18 occurred, and there was a problem that a polycrystalline silicon layer could not serve as a whole surface single crystal. This invention was made in order to cancel the above problems, and an object of an invention is to obtain the zone fusion type single crystal semiconductor layer forming device which is a large area and can form a quality single crystal semiconductor layer.

the means for solving [problem] -- the zone fusion type single crystal semiconductor layer forming device concerning this invention, The many crystals formed on an insulating layer and the insulating layer or the sample containing a noncrystalline semiconductor layer is put on a stand, It separates from the upper surface of a sample and provides the source of 1st longitudinal-like radiation heating which irradiates with and heats this sample and fuses the above-mentioned semiconductor layer beltlike in parallel, It separates from the undersurface of a stand and provides in parallel the source of the 2nd Sacrifice heating which irradiates with and heats a sample fixed to this stand, It moves in the almost right-angled direction relatively to the source of 1st longitudinal-like radiation heating in the source of the 2nd radiation heating at the longitudinal direction of the source of 1st longitudinal-like radiation heating by a transportation device, A beltlike fusion field is moved on an insulating layer, and it is this beltlike Melting!! At the time of Transfer vI of a field, concentration of front territory Stop following a beltlike fusion field is made high, and heating of the source of the 2nd radiation heating is controlled by an l][+ thermal control means to make low temperature of the back field following a beltlike fusion field.

[Function] It is quantity (it carries out and controlled to make low temperature of a back field following a beltlike fusion field.) about temperature of a front field which follows a beltlike field like movement of a beltlike fusion field of a sample in the present invention. Therefore, beltlike Melting!! A temperature gradient in a solid-liquid interface in a trailing edge of a field becomes large.

[Example] Hereinafter, the example of this invention is described about a figure. Drawing 1 is a figure showing the zone fusion type single crystal semiconductor layer forming device which is an example of this invention. when the composition of this device is explained, in a figure, wafer retainer board 14 is a product made from carbon -- that thickness -- 611Im~10111. -- that shape is made into a square or a rectangle, and it comes out. Sample wafer 3o is placed on wafer retainer board 14. This sample wafer is constituted like the sample wafer of Drawing 4. That is, the silicon dioxide layer, the polycrystalline silicon layer, the silicon dioxide layer, and the nitriding silicon layer are laminated and formed in this order on the silicon substrate of a single crystal, and the polycrystalline silicon layer which should be carried out [ single crystal ]-izing is inserted in the insulating layer. Tubular lamp 12 for fusion object formation which has collection mirror 120 in parallel with this upper surface is formed in the upper part of sample wafer 30. Collection mirror 120 carries out the condensing irradiation of the light of tubular lamp 12 for fusion object formation at sample wafer 3*, heats this, and fuses a polycrystalline silicon layer beltlike between the insulating layers of the upper and lower sides. It is ten in the lower part of wafer retainer board 14 in parallel with the undersurface of this wafer retainer board to the tube axis of tubular lamp 12 for fusion object formation, and parallel! It is mutually out of order, and A casing-like lamp 19a-19j for S board heating separates an interval, crowds, and they are installation It has been. The light from tubular lamp 19for daytime temporary heating a~19j irradiates with all the undersurfaces of wafer retainer board 14, heats this, and heats the silicon substrate of the single crystal of sample wafer 30 by it. It is being fixed mutually and tubular lamp 19a~19J for substrate heating and wafer retainer board 14 are Transfer gtJ devices (not shown), The tube axis of tubular lamp 12 for fusion object formation is made to move relatively wafer retainer board 14 and tubular lamp 19a~19j for substrate heating on which sample wafer 30 was placed to tubular lamp 12 for fusion object formation in the arrow 15 almost right-angled direction. It is scanned while this is irradiated with the whole region of sample wafer 30 with the light of tubular lamp 12 for fusion object formation from -, and band-like r8 Melting region of a polycrystalline silicon layer is moved in the scanning direction between the insulating layers of the upper and lower sides. Position sensing device 21 is formed in the flank of wafer retainer board 14, and this position sensing device detects the position to sample wafer 30 of a beltlike fusion field which moves. Position sensing device 21 is connected to subpart device 20, and this control device 20 is connected to each tubular lamp 19a~19j for substrate heating. System m device 2o controls the electric power supplied to each tubular lamp for substrate heating based on position sensing device 21 output, and controls the temperature distribution of sample wafer 3o by this while it supplies electric power to each tubular lamp 19a~19J for substrate heating including a power supply. Next, the case where this device performs zone fusion is explained. It irradiates with all the undersurfaces of wafer retainer board 14 by the light from tubular lamp 19for substrate heating a~19j, and heats, It is tubular lamp 19a~19j for substrate heating about wafer retainer board 14 on which it irradiated with the upper surface of sample wafer 30 by the light from tubular lamp 12 for fusion object formation, and heated, and sample wafer 30 was placed by the moving system in this state, The tube axis of tubular lamp 12 for fusion object formation is relatively moved in the arrow 15 almost right-angled direction to tubular lamp 12 for fusion object formation. At this time, while being irradiated with sample wafer 3o by the light from tubular lamp 12 for fusion object formation, it is scanned, The beltlike fusion field of the polycrystalline silicon layer of about 2 IllII width produces between the insulating layers of sample wafer 3o, and between insulating layers is moved to this fusion field by the another side end from the one side end of sample wafer 30, carrying out crystal growth in that trailing edge. At this time, the position to sample wafer 30 of a beltlike fusion field is detected by position sensing device 21, and it is based on this position sensing device 21 output, and is control I device 2o, It is controlled to fall according to movement of a beltlike fusion field from the power supply to each tubular lamp for substrate heating under the front field where the power supply to each tubular lamp for substrate heating under back wta following a beltlike fusion field follows a beltlike fusion field, and is this, The temperature distribution of the scanning direction of sample wafer 3 * is controlled so that the temperature of the front field following a beltlike fusion field becomes high and the temperature of the back field following a beltlike fusion field becomes low. Namely, Drawing 2 (as shown in A>, the power supply to each tubular lamp 19a~19c for substrate heating under the method field of Contact following a beltlike fusion field is Continuing (at this time [ Controlled to fall from the power supply of each tubular lamp 196~19J for substrate heating under a front field. ]) to a beltlike fusion field) The temperature distribution of the scanning direction of sample wafer 30 is Drawing 2 (it is shown in B> like). 1r of the front field following the beltlike fusion field on tubular lamp 196~19j for substrate heating! It is controlled so that 120 becomes high and temperature 21 of back fiI Stop following the beltlike fusion field on tubular lamp 19a~19c for M temporary heating becomes low. for this reason, cingulate sulcus!!! the temperature gradient in connection with the re-crystal in the trailing edge of a field becomes steep, and solidification latent heat breathes out -- etc. -- the factor which bars heat dissipation is removed A crystal growth side turns into a field perpendicular to the scanning direction, generating of the segregation of impurities, etc. is suppressed, and form yi of the quality single-crystal-silicon layer can be easily carried out on a silicon dioxide layer by a large area. It is although the above-mentioned example showed the case where a plurality of tubular lamps were used for heating of a substrate, A substrate may be heated using a plurality of line heaters, and a wafer retainer board is made into the anode, it may be made to heat a substrate by making a plurality of line arc torches into the negative pole, and the same effect as the above-mentioned example is Qin(ed) also in these cases. Although the above-mentioned example showed the case where a polycrystalline silicon layer was single-crystal-ized, as a single-crystal-ized layer, it may be other multi-crystal semiconductor layers and noncrystalline semiconductor layers, and produces the above-mentioned example and the effect of the A also in this case. Although the above-mentioned example showed the case where the polycrystalline silicon layer on a silicon dioxide layer was crystallized 11 times, the polycrystalline silicon layer on other insulating layers may be single-crystal-ized, and the same effect as the above-mentioned example is produced also in this case. It is although the case where controlled the electric power supplied to the tubular lamp for substrate heating by the above-mentioned example, and the temperature distribution of a sample wafer was controlled was shown, The thermal insulation which intercepts the light from the tubular lamp for substrate heating is provided fixed to the tubular lamp for fusion belt formation, And this thermal insulation is inserted so that it may be located between a wafer retainer board and the tubular lamp for substrate heating corresponding to the back field following the beltlike fusion field of a sample, and it may be made to control the temperature of a sample wafer.

[Effect of the Invention] By the present invention, the many crystals formed on an insulating layer and the insulating layer or the sample containing a noncrystalline semiconductor layer is put on a stand as mentioned above, It separates from the upper surface of a sample and provides a source of 1st longitudinal-like radiation heating which irradiates with and heats this sample and fuses the above-mentioned semiconductor layer beltlike in parallel, the [ which separates from the undersurface of a stand, and irradiates with and heats a sample fixed to this stand in parallel ] -- 2I! Provide Additive heat source. It moves in the almost right-angled direction relatively to a source of 1st longitudinal-like radiation heating in a source of the 2nd radiation heating at a longitudinal direction of a source of 1st longitudinal-like radiation heating by a transportation device, A beltlike fusion field is moved on an insulating layer, humidity of a front field following a beltlike fusion field is made high at the time of movement of this beltlike fusion field, and it is method f of Salivation to beltlike Melting Ft11 field! Heating of a source of the 2nd radiation heating was controlled by a heating control means to make temperature of four regions low. Therefore, a zone fusion type single crystal semiconductor layer forming device which is a large area and can form a quality single crystal semiconductor layer on insulation 1 can be obtained.

[Brief Description of the Drawings]

Drawing 1 is a figure showing the zone fusion type single crystal semiconductor layer forming device which is an example of this invention. Drawing 2 (A> and (B) are the figures for explaining control of the temperature distribution of the scanning direction of the sample wafer in a conductor layer forming device to zone fusion type single crystal * which is an example of this invention.) Drawing 3 is a figure showing the zone fusion type single crystal semiconductor layer forming device which used the conventional carbon heater. Drawing 4 is a sectional view of a sample wafer. Drawing 5 is a figure showing the zone fusion type single crystal semiconductor layer forming device which used the conventional tubular lamp. Drawing 6 (A) is a sectional view of Sample 1 Ha under zone fusion, and Drawing 6 (B) is a top view containing the polycrystalline silicon layer of 6th [ The ] figure <A. As for a sample wafer and 6, in 3 and 30, in a figure, the silicon substrate of a single crystal and 7.9 are silicon dioxide layers, 8 -- a polycrystalline silicon layer and 10 -- as for a wafer retainer board and 19a~19j, the tubular lamp for fusion object formation and 120 are [ a control device and 21 ] position sensing devices the tubular lamp for substrate heating, and 20 a reflective mirror and 14 a nitriding silicon layer and 12. Each same-among figure numerals show a same or considerable portion. The representative Oiwa [ Masuo ] 1st figure figure 2 Drawing 3 Drawing 4