Single-crystal wafer and method for producing same

Abstract

This single-crystal wafer is a thin plate-like body having: a first main surface; a second main surface; and lateral surfaces connecting the first main surface and the second main surface. The thickness of the thin plate-like body is not more than 1 mm, and at least a portion of the first main surface, the second main surface, and the lateral surfaces has a transfer surface derived from a shaping tool.

Description

Single crystal wafer and its manufacturing method

[0001] The present disclosure relates to a single crystal wafer and a method for manufacturing the same. The term "wafer" generally refers to a thin plate-like body cut from a semiconductor single crystal ingot, such as a semiconductor single crystal cut into a thin plate (Kojien) or a semiconductor crystal processed into a plate-like body several hundred micrometers thick (Physical and Chemical Encyclopedia). However, the "wafer" in the present disclosure does not have to be cut from a single crystal ingot as long as it is a thin plate-like body with a thickness of 1 mm or less, and the material is not limited to semiconductors.

[0002] Single crystal wafers of silicon, gallium arsenide, germanium, etc. are typically obtained by producing single crystal ingots using ultra-high-quality raw materials using the CZ method or other methods, and then slicing the single crystal ingots into thin sheets using a multi-wire saw or other tool. Because the width of a single wire saw is approximately the same as the thickness of a single crystal wafer, approximately half of the single crystal ingot becomes kerf loss. Furthermore, because single crystal ingots are often made with additives or as alloys, their leading and trailing ends contain additives and exhibit segregation of their composition, making them difficult to reuse. As a result, approximately 70% of the total ingot volume must be discarded. Furthermore, in the production of solar cell wafers, the leading and trailing ends of a single crystal ingot are cut off to create a cylindrical single crystal, and four edges are then cut and removed to form a rectangular shape, resulting in loss of the four edges. Furthermore, these manufacturing processes require a significant amount of time, electricity, and other energy, resulting in significant losses. In other words, conventional single crystal wafer manufacturing methods inevitably result in significant losses of ultra-high-quality raw materials, time, and energy. Furthermore, after cutting, disposal of the sludge becomes an issue, and post-processing is required, such as cleaning the sludge and removing distortions and undulations that occur during cutting. These enormous losses and post-processing processes significantly increase costs.

[0003] In order to eliminate these enormous losses and post-processing steps, increase the utilization rate of ultra-high quality raw materials, and significantly reduce costs, the present inventors have been working for many years on the direct production of single crystal wafers. In Patent Document 1, they proposed a method for producing high-quality silicon crystal ribbons (wafers) using a shaping vessel and shaping tool (also called a mold) made of carbon or quartz glass. This manufacturing method comprises (a) a step of heating raw material crystals in a shaping vessel set to a predetermined atmosphere to form a melt, (b) a step of placing the melt in a shaping jig placed in the shaping vessel, and (c) a step of cooling the melt from one end of the shaping jig to crystallize (Claim 1). (a) A shaping jig having a recess formed by arranging multiple plate-shaped trays horizontally or vertically with gaps between them is configured to be movable from one end of the shaping vessel to the other in a horizontal plane, (b) placing the raw material at one end of the shaping vessel, and (c) moving the shaping jig from the other end of the shaping vessel to place the melt in the recess (Claim 3). This is intended for the production of polycrystalline wafers, but we also proposed a method of producing plate-shaped single-crystal silicon by setting a plate-shaped seed crystal with a thickness equal to the gap between the plate-shaped trays at one end of the plate-shaped tray (seed crystal horizontal arrangement) (Proposal 1) (0017).

[0004] Patent No. 2947529

[0005] However, Proposal 1 was merely an idea, and it was not possible to actually manufacture single-crystal silicon wafers. The reason for this is thought to be that when the seed crystal was placed horizontally, the solid-liquid interface between the melt and the seed crystal could not be maintained in a straight line due to convection of the melt. In other words, Proposal 1 was structurally difficult to realize due to the horizontal placement of the seed crystal. Furthermore, the plate-shaped seed crystal used in Proposal 1 was obtained by cutting it into thin plates, just like conventional single-crystal wafers, which resulted in loss and increased costs.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a single crystal wafer and a method for manufacturing the same that can eliminate the enormous loss of ultra-high quality raw materials, time, energy, etc., and post-processing steps, increase the utilization rate of ultra-high quality raw materials, and significantly reduce costs.

[0007] One aspect of the present disclosure relates to a single crystal wafer comprising a thin plate-like body having a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface, wherein the thickness of the thin plate-like body is 1 mm or less, and at least a portion of the first main surface, the second main surface, and the side surface have a transferred surface from a shaping jig.

[0008] The single crystal wafer according to one embodiment of the present disclosure is manufactured directly without using an ingot, thereby eliminating the need for post-processing and the enormous loss of ultra-high quality raw materials, time, energy, etc., thereby increasing the utilization rate of ultra-high quality raw materials and significantly reducing costs.

[0009] In one aspect of the present disclosure, it is preferable that at least a portion of the first main surface has a transferred surface from the shaping jig, that the first main surface is made of the transferred surface from the shaping jig, that the first main surface and the second main surface are made of the transferred surfaces from the shaping jig, that at least a portion of the transferred surface has a textured structure, or that the thin plate-like body is rectangular or square.

[0010] This reduces the number of processes such as processing and cleaning, improves the utilization rate of raw materials, and further reduces costs. In addition, when single-crystal wafers are used in light-receiving devices such as solar power generation devices, the textured structure reduces reflection loss and improves the utilization rate of light.

[0011] In one aspect of the present disclosure, the single crystal wafer is preferably made of an inorganic material, a semiconductor, or germanium.

[0012] This improves utilization of expensive raw materials, further reducing costs.

[0013] Another aspect of the present disclosure comprises a first step of arranging a bulk seed crystal, raw material for crystal, and a shaping jig in a shaping vessel in this order from the bottom; a second step of raising the temperature of the shaping vessel, which has been set to a predetermined atmosphere and a predetermined temperature gradient, to melt the raw material, leaving at least a portion of the seed crystal unmelted as a solid, and bringing the melt into contact with the remaining solid seed crystal; a third step of accommodating the melt in the shaping jig; and a fourth step of lowering the temperature of the shaping vessel to convert the melt into a single crystal, wherein the seed crystal and the raw material are the same material; the predetermined temperature gradient is set such that the temperature of a first region in which the seed crystal is placed in the first step is lower than the temperature of a second region in which the raw material and the shaping jig are placed; the shaping jig is composed of two or more plate-like trays, and the plate-like tray has a recess on one surface and a first communication part from the recess to the first region; the two or more plate-like trays are stacked horizontally with the one surface facing the same direction, and are arranged while maintaining communication between the recess and the first region via the first communicating portion; the recess has a depth of 1 mm or less; the shaping jig is configured to be movable vertically downward; and in the third step, the melt is accommodated in the recess via the first communicating portion by moving the shaping jig vertically downward with an external force.

[0014] Another aspect of the present disclosure comprises a first step of arranging a bulk seed crystal, a shaping jig, crystal raw material, and a raw material pushing jig in that order from the bottom in a shaping vessel; a second step of raising the temperature of the shaping vessel, which has been set to a predetermined atmosphere and a predetermined temperature gradient, to melt the raw material and leave at least a portion of the seed crystal as a solid, without melting; a third step of accommodating the melt in the shaping jig and bringing the melt into contact with the seed crystal, which remains as a solid; and a fourth step of lowering the temperature of the shaping vessel to form a single crystal, wherein the seed crystal and the raw material are the same material; the predetermined temperature gradient is set so that the temperature of a first region where the seed crystal is placed in the first step is lower than the temperature of a second region where the raw material and the shaping jig are placed; and the shaping jig is composed of two or more plate-like trays. the plate-shaped tray has a recess on one surface, a first communicating portion from the recess to the first region, and a second communicating portion from the recess to the raw material side; two or more of the plate-shaped trays are stacked horizontally with the one surface oriented in the same direction, and are arranged while maintaining communication between the recess and the first region via the first communicating portion; the recess has a depth of 1 mm or less; the pushing jig is configured to be movable vertically downward; and in the third step, the pushing jig is moved vertically downward to accommodate the melt in the recess via the second communicating portion and bring the melt into contact with the seed crystal via the first communicating portion.

[0015] According to the method for producing a single crystal wafer of another aspect of the present disclosure, it is possible to directly produce a single crystal wafer without using an ingot, thereby eliminating the enormous loss of ultra-high quality raw materials, time, energy, etc., and post-processing, thereby increasing the utilization rate of the ultra-high quality raw materials and significantly reducing costs.

[0016] In another aspect of the present disclosure, it is preferable that the other surface of the plate-shaped tray and the bottom surface of the recess are flat, and the shape of the bottom surface is rectangular or square.

[0017] This reduces the number of processes such as processing and cleaning, improves the utilization rate of raw materials, and further reduces costs.

[0018] In another aspect of the present disclosure, it is preferable that the other surface of the plate-shaped tray and at least a part of the bottom surface of the recess have a textured structure.

[0019] This reduces the number of processes such as processing and cleaning, improves the utilization rate of raw materials, and further reduces costs.

[0020] In another aspect of the present disclosure, it is preferable that the same substance is an inorganic substance, the inorganic substance is a semiconductor, or the semiconductor is germanium.

[0021] This improves utilization of expensive raw materials, further reducing costs.

[0022] 1 shows a manufacturing apparatus used in the manufacturing method of this embodiment; 2 shows the manufacturing apparatus during the third step; 3 shows the manufacturing apparatus used in the manufacturing method of this embodiment; 4 shows the manufacturing apparatus during the third step; 5 shows the manufacturing apparatus used in the manufacturing method of this embodiment; 6 shows the manufacturing apparatus during the third step; 7 shows a germanium single crystal wafer on the left and a germanium polycrystalline wafer on the right.

[0023] Preferred embodiments of the present disclosure will be described in detail below. Note that the embodiments described below do not unduly limit the content of the present disclosure described in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0024] [Single Crystal Wafer] The single crystal wafer of this embodiment is a thin plate-like body having a first main surface, a second main surface, and a side surface connecting the first main surface and the second main surface, and the thickness of the thin plate-like body is 1 mm or less, and at least a portion of the first main surface, the second main surface, and the side surface have a transferred surface from the shaping jig.

[0025] Because it is a single crystal wafer manufactured directly without using an ingot, it eliminates the huge waste of ultra-high quality raw materials, time, energy, etc., as well as post-processing, thereby increasing the utilization rate of ultra-high quality raw materials and significantly reducing costs.

[0026] In the single crystal wafer of this embodiment, it is preferable that at least a portion of the first main surface has a transferred surface from the shaping jig, that the first main surface is composed of the transferred surface from the shaping jig, that the first main surface and the second main surface are composed of the transferred surfaces from the shaping jig, that at least a portion of the transferred surface has a textured structure, or that the thin plate-like body is rectangular or square. The first main surface may also have a textured structure. This reduces processes such as processing and cleaning, improves raw material utilization, and further reduces costs. Furthermore, when the single crystal wafer is used in a light-receiving device such as a solar power generation device, the textured structure reduces reflection loss and improves light utilization. Furthermore, the plane orientation of the first main surface may be (100), (110), (111), etc.

[0027] The single crystal wafer of this embodiment is not particularly limited as long as it can be produced from any material, but is preferably made of an inorganic material. Examples of inorganic materials include semiconductors, oxides, metals, alloys, and halides. Examples of semiconductors include germanium. This embodiment improves the utilization rate of expensive raw materials, further reducing costs.

[0028] The thickness of the thin plate-shaped single crystal wafer of this embodiment is preferably 0.5 mm or less, and more preferably 0.3 mm or less. This allows for an increase in the number of single crystal wafers obtained per raw material. There is no particular lower limit to the thickness of the thin plate-shaped single crystal wafer as long as it can be produced, but from the perspective of strength, it is preferably 0.1 mm or more, and more preferably 0.2 mm or more.

[0029] [Method for Manufacturing a Single Crystal Wafer] The method for manufacturing a single crystal wafer according to this embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0030] The method for producing a single crystal wafer of this embodiment includes a first step (FIG. 1) of arranging bulk seed crystal 12, crystal raw material 13, and shaping jig 14 in order from bottom to top in shaping vessel 11; a second step of heating shaping vessel 11, which is set to a predetermined atmosphere and a predetermined temperature gradient, to turn raw material 13 into melt 15, leaving at least a portion of seed crystal 12 unmelted as a solid, and bringing melt 15 into contact with seed crystal 12 remaining as a solid; a third step (FIG. 2) of placing melt 15 in shaping jig 14; and a third step of lowering the temperature of shaping vessel 11 to melt 15. The seed crystal 12 and the raw material 13 are the same material, and the predetermined temperature gradient is set so that the temperature of a first region 16 in which the seed crystal 12 is placed in the first step is lower than the temperature of a second region 17 in which the raw material 13 and the shaping jig 14 are placed, and the shaping jig 14 is composed of two or more plate-like trays 18, and each plate-like tray 18 has a recess 19 on one side and a first communication part 20 from the recess 19 to the first region 16, and the two or more plate-like trays 18 are stacked horizontally with one side of the tray facing in the same direction. The recess 19 is arranged so as to maintain communication between the recess 19 and the first region 16 via the first communicating portion 20, the depth of the recess 19 is 1 mm or less, the shaping jig 14 is configured to be movable vertically downward, and in the third step, the shaping jig 14 is moved vertically downward by an external force, thereby accommodating the melt 15 in the recess 19 via the first communicating portion 20.

[0031] Because single crystal wafers can be manufactured directly without using ingots, it is possible to eliminate the huge waste of ultra-high quality raw materials, time, energy, etc., as well as post-processing, increase the utilization rate of ultra-high quality raw materials, and significantly reduce costs.

[0032] In the method for producing a single crystal wafer according to this embodiment, the seed crystal 12 is obtained by processing a bulk single crystal. The other surface of the plate-shaped tray 18 and the bottom surface of the recess 19 are preferably flat, and the shape of the bottom surface of the recess 19 is preferably a parallelogram, rectangle, rhombus, or square. Alternatively, at least a portion of the other surface of the plate-shaped tray 18 or the bottom surface of the recess 19, or either one of them, may have a textured structure. This reduces the number of processes, such as processing and cleaning, and improves the utilization rate of the raw material 13, further reducing costs.

[0033] In the method for producing a single crystal wafer of this embodiment, the plane orientation of the seed crystal 12 in the same direction as one surface of the plate-like tray 18 may be any plane orientation, such as (100), (110), (111), or even a plane orientation inclined at a required angle from these reference planes. Single crystal wafers in which the plane orientation of the first main surface is controlled to (100), (110), (111), or the like, can be easily produced. Furthermore, in the method for producing a single crystal wafer of this embodiment, the shape of the bottom of the recess 19 may be any shape; for example, if a disk-shaped single crystal wafer is required, the shape of the bottom of the recess 19 may be circular. This allows for the easy production of multiple single crystal wafers of any shape.

[0034] In the method for producing a single crystal wafer according to this embodiment, the depth of recess 19 is preferably 0.5 mm or less, and more preferably 0.3 mm or less. The lower limit of the depth of recess 19 is not particularly limited as long as a single crystal wafer can be produced, but from the viewpoint of strength, it is preferably 0.1 mm or more, and more preferably 0.2 mm or more.

[0035] In the method for producing a single crystal wafer according to this embodiment, the materials of the seed crystal 12 and the raw material 13 are not particularly limited as long as they can produce a single crystal wafer; however, they are preferably the same material, and more preferably inorganic. The same material may have different purities for the seed crystal 12 and the raw material 13; for example, the seed crystal 12 may be 6N and the raw material 13 may be 4N. Examples of inorganic materials include semiconductors, oxides, metals, alloys, and halides. Examples of semiconductors include germanium. This improves the utilization rate of expensive raw materials, further reducing costs.

[0036] In the method for producing a single crystal wafer according to the present embodiment, the predetermined atmosphere is not particularly limited as long as it is inert to the seed crystal 12, raw material 13, melt 15, shaping vessel 11, and shaping jig 14, but examples thereof include argon, nitrogen, and vacuum.

[0037] In the method for manufacturing a single crystal wafer according to this embodiment, the shape of first communicating portion 20 is not particularly limited as long as the flow of melt 15 and atmosphere between recess 19 and first region 16 is ensured.

[0038] In the method for producing a single crystal wafer according to this embodiment, plate-like tray 18 may have a second communicating portion (not shown) extending upward from recess 19. In the third step, gas within recess 19 escapes upward via the second communicating portion, which makes it easier for melt 15 to fill recess 19, thereby increasing the yield of single crystal wafers. The shape of the second communicating portion is not particularly limited as long as it ensures the flow of melt 15 and the atmosphere between recess 19 and the upper portion.

[0039] In the method for manufacturing a single crystal wafer according to this embodiment, the wall surface of the inner periphery of the recess 19 may be chamfered. This makes it possible to eliminate the need for a separate chamfering process using a chamfering device and a cleaning process. Chamfering improves the shear strength, reducing breakage during removal of the single crystal wafer and subsequent chipping and breakage during handling of the wafer.

[0040] In the method for producing a single crystal wafer according to this embodiment, the interface between the seed crystal 12 and the single crystal wafer may be cut by a laser, or the chamfered, drawn portion of the seed crystal 12 may be cut by a laser. Because cutting is not performed using a wire saw, the seed crystal 12 can be reused without the need for a sludge cleaning process or a processing strain removal process. Laser cutting can also be used to easily cut wafers, as is done for scribing wafers.

[0041] In the method for manufacturing a single crystal wafer of this embodiment, the shaping jig 14 may be fixed and the shaping vessel 11 may be moved vertically upward to accommodate the melt 15 in the recess 19 via the first communication part 20, or the manufacturing apparatus may be configured upside down.

[0042] Another method for manufacturing a single crystal wafer according to this embodiment will be described with reference to FIGS.

[0043] Another method for manufacturing a single crystal wafer according to this embodiment includes a first step (FIG. 3) of arranging bulk seed crystal 12, shaping jig 14, crystal raw material 13, and raw material 13 pushing jig 22 in order from the bottom in shaping vessel 11; a second step of heating shaping vessel 11, which has been set to a predetermined atmosphere and a predetermined temperature gradient, to turn raw material 13 into melt 15 and leave at least a portion of seed crystal 12 as a solid; a third step (FIG. 4) of placing melt 15 in shaping jig 14 and bringing melt 15 into contact with seed crystal 12, which remains as a solid; and a third step of lowering the temperature of shaping vessel 11 to turn melt 15 into a single crystal. The seed crystal 12 and the raw material 13 are made of the same material, and the predetermined temperature gradient is set so that the temperature of the first region 16 in which the seed crystal 12 is placed in the first step is lower than the temperature of the second region 17 in which the raw material 13 and the shaping jig 14 are placed, and the shaping jig 14 is composed of two or more plate-like trays 18, and each plate-like tray 18 has a recess 19 on one side, a first communication part 20 from the recess 19 to the first region 16, and a second communication part 21 from the recess 19 to the raw material 13 side, and the two or more plate-like trays 18 are stacked horizontally with one side facing in the same direction. The recess 19 is positioned so as to maintain communication between the recess 19 and the first region 16 via the first communicating portion 20, the recess 19 has a depth of 1 mm or less, and the pushing jig 22 is configured to be movable vertically downward. In the third step, the pushing jig 22 is moved vertically downward to accommodate the melt 15 in the recess 19 via the second communicating portion 21 and bring it into contact with the seed crystal 12 via the first communicating portion 20.

[0044] In other methods for manufacturing single crystal wafers according to this embodiment, the pushing jig 22 may be fixed and the shaping vessel 11 may be moved vertically upward to accommodate the melt 15 in the recess 19 via the second communicating portion 21, or the manufacturing apparatus may be configured upside down.

[0045] Another method for manufacturing a single crystal wafer according to this embodiment will be described with reference to FIGS.

[0046] Another method for manufacturing a single crystal wafer according to this embodiment includes a first step (FIG. 5) of arranging a bulk seed crystal 12, a shaping jig 14, and crystal raw material 13 in order from the bottom into a shaping vessel 11; a second step of increasing the temperature of the shaping vessel 11, which has been set to a predetermined atmosphere and a predetermined temperature gradient, to turn the raw material 13 into a melt 15, while leaving at least a portion of the seed crystal 12 unmelted as a solid; a third step (FIG. 6) of placing the melt 15 in the shaping jig 14 and bringing the melt 15 into contact with the seed crystal 12 remaining as a solid; and a fourth step of decreasing the temperature of the shaping vessel 11 to convert the melt 15 into a single crystal. The seed crystal 12 and the raw material 13 are made of the same material, and the predetermined temperature gradient is set so that the temperature of a first region 16 in which the seed crystal 12 is placed in the first step is lower than the temperature of a second region 17 in which the raw material 13 and the shaping jig 14 are placed, and the shaping jig 14 is composed of two or more plate-like trays 18, and each plate-like tray 18 has a recess 19 on one side, a first communication part 20 from the recess 19 to the first region 16, and a second communication part 21 from the recess 19 to the raw material 13 side, and the two or more plate-like trays 18 are stacked horizontally with one side facing in the same direction. The recess 19 is positioned so as to maintain communication between the recess 19 and the first region 16 via the first communicating portion 20, and the depth of the recess 19 is 1 mm or less. In the third step, the melt 15 is accommodated in the recess 19 via the second communicating portion 21 due to its own weight, and is brought into contact with the seed crystal 12 via the first communicating portion 20.

[0047] The other single crystal wafer manufacturing method of this embodiment also allows single crystal wafers to be manufactured directly without using an ingot, thereby eliminating the enormous loss of ultra-high quality raw materials, time, energy, etc., and post-processing, thereby increasing the utilization rate of ultra-high quality raw materials and significantly reducing costs.

[0048] In other single crystal wafer manufacturing methods according to this embodiment, the depth of the recess 19 may be any depth greater than 1 mm, such as 10 mm or 20 mm, and the shape of the bottom surface of the recess 19 may also be any desired shape. It is possible to easily manufacture a plurality of single crystal plates having any desired thickness, such as 10 mm or 20 mm, and any desired shape. For example, if the shape of the bottom surface of the recess 19 is a circular concave surface or a circular convex surface, it is also possible to easily manufacture a plurality of convex or concave lenses.

[0049] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to FIGS. 1 and 2. FIG.

[0050] In the first step ( FIG. 1 ), a bulk germanium seed crystal (6N purity) 12, a germanium raw material (6N purity) 13, and a shaping jig 14 were placed in a graphite shaping container 11, in this order from bottom to top. Here, the region where the seed crystal 12 is placed is referred to as a first region 16, and the region where the raw material 13 and the shaping jig 14 are placed is referred to as a second region 17. The shaping jig 14 is composed of two or more graphite plate-like trays 18. Each plate-like tray 18 has a recess 19 on one surface and a first communication portion 20 from the recess 19 to the first region 16. The two or more plate-like trays 18 are stacked horizontally with one surface facing the same direction, and are arranged such that communication between the recess 19 and the first region 16 is maintained via the first communication portion 20. The recess 19 has a depth of 0.5 mm, a square bottom surface of 100 mm x 100 mm, and the shaping jig 14 is configured to be movable vertically downward.

[0051] In the second step, the shaping vessel 11, which is set to an argon or vacuum atmosphere and a predetermined temperature gradient, is heated to near the melting point (938°C) of the germanium raw material 13 to turn the raw material 13 into a melt 15, leaving at least a portion of the seed crystal 12 unmelted and as a solid, and the melt 15 is brought into contact with the remaining solid seed crystal 12. The predetermined temperature gradient is set so that the temperature of the first region 16 is lower than the temperature of the second region 17.

[0052] In the third step, the shaping jig 14 was moved vertically downward by an external force (downward arrow in Figure 1 ), so that the melt 15 was accommodated in the recess 19 of the plate-like tray 18 constituting the shaping jig 14 via the first communication part 20 ( Figure 2 ).

[0053] In the fourth step, the temperature of the shaping vessel 11 was lowered while maintaining a predetermined temperature gradient, and crystal growth was carried out from the seed crystal 12 side of the melt 15, yielding a germanium single crystal wafer measuring 100 mm x 100 mm x 0.5 mm thick. The left side of Figure 7 shows a germanium single crystal wafer, and the right side shows a germanium polycrystalline wafer produced without a seed crystal. The wafer on the left has a uniform reflection pattern on the surface, indicating that it has a uniform plane orientation, i.e., is a single crystal. On the other hand, the wafer on the right has regions with different reflection patterns, and each region is single crystal, indicating that it is an aggregate of single crystals with different plane orientations.

[0054] Because it is possible to manufacture single crystal wafers directly without using ingots, it is possible to eliminate the huge waste of ultra-high quality raw materials, time, energy, etc., as well as post-processing, increase the utilization rate of ultra-high quality raw materials, and significantly reduce costs.

[0055] Although the present embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and advantages of the present disclosure. Therefore, all such modifications are included within the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader or similar meaning may be replaced with that different term anywhere in the specification or drawings. Furthermore, the configuration of the present embodiment is not limited to that described in the present embodiment, and various modifications are possible.

[0056] REFERENCE SIGNS LIST 11 shaping vessel, 12 seed crystal, 13 crystal raw material, 14 shaping jig, 15 melt, 16 first region, 17 second region, 18 plate-shaped tray, 19 recess, 20 first communicating portion, 21 second communicating portion

Claims

1. A single crystal wafer comprising a thin plate-like body having a first main surface, a second main surface, and a side surface connecting the first and second main surfaces, wherein the thickness of the thin plate-like body is 1 mm or less, and at least a portion of the first main surface, the second main surface, and the side surface have transferred surfaces from a shaping jig.

2. A single crystal wafer according to claim 1, wherein at least a portion of said first main surface has a transferred surface from said shaping jig.

3. A single crystal wafer according to claim 1, wherein the first main surface is a surface transferred from the shaping jig.

4. A single crystal wafer according to claim 1, wherein the first main surface and the second main surface are transferred surfaces from the shaping jig.

5. The single crystal wafer according to claim 1, wherein at least a portion of the transfer surface has a textured structure.

6. The single crystal wafer according to claim 1, wherein the thin plate-like body is rectangular or square.

7. A single crystal wafer according to any one of claims 1 to 6, characterized in that it is made of an inorganic material.

8. A single crystal wafer according to claim 7, characterized in that the single crystal wafer is made of a semiconductor.

9. The single crystal wafer according to claim 8, characterized in that the single crystal wafer is made of germanium.

10. A method for producing a crystal single crystal, comprising: a first step of arranging a bulk seed crystal, raw crystal material, and a shaping jig in a shaping vessel in this order from the bottom; a second step of heating the shaping vessel, which is set to a predetermined atmosphere and a predetermined temperature gradient, to melt the raw material, leaving at least a portion of the seed crystal unmelted as a solid, and bringing the melt into contact with the seed crystal that remains as a solid; a third step of placing the melt in the shaping jig; and a fourth step of lowering the temperature of the shaping vessel to produce a single crystal, wherein the seed crystal and the raw material are the same material; the predetermined temperature gradient is set so that the temperature of a first region in which the seed crystal is placed in the first step is lower than the temperature of a second region in which the raw material and the shaping jig are placed; the shaping jig is composed of two or more plate-like trays, and each plate-like tray has a recess on one surface and a first communication portion from the recess to the first region; a method for manufacturing a single crystal wafer, wherein two or more of the plate-like trays are stacked horizontally with the orientation of one of the surfaces facing the same direction, and are arranged while maintaining communication between the recess and the first region through the first communicating portion; the depth of the recess is 1 mm or less; the shaping jig is configured to be movable vertically downward; and in the third step, the melt is accommodated in the recess via the first communicating portion by moving the shaping jig vertically downward with an external force.

11. A method for producing a crystal material comprising: a first step of arranging a bulk seed crystal, a shaping jig, crystal raw material, and a raw material pushing jig in a shaping vessel in this order from the bottom; a second step of heating the shaping vessel, which has been set to a predetermined atmosphere and a predetermined temperature gradient, to melt the raw material and leave at least a portion of the seed crystal unmelted as a solid; a third step of placing the melt in the shaping jig and bringing the melt into contact with the seed crystal, which remains solid; and a fourth step of lowering the temperature of the shaping vessel to produce a single crystal; wherein the seed crystal and the raw material are the same material; the predetermined temperature gradient is set so that the temperature of a first region where the seed crystal is placed in the first step is lower than the temperature of a second region where the raw material and the shaping jig are placed; and the shaping jig is composed of two or more plate-like trays. the plate-shaped tray has a recess on one surface, a first communicating portion from the recess to the first region, and a second communicating portion from the recess to the raw material side; two or more of the plate-shaped trays are stacked horizontally with the one surface oriented in the same direction, and are arranged while maintaining communication between the recess and the first region via the first communicating portion; the recess has a depth of 1 mm or less; the pushing jig is configured to be movable vertically downward; and in the third step, the pushing jig is moved vertically downward to accommodate the melt in the recess via the second communicating portion and bring it into contact with the seed crystal via the first communicating portion.

12. A method for producing a single crystal wafer according to claim 10 or 11, wherein the other surface of the plate-like tray and the bottom surface of the recess are flat, and the shape of the bottom surface is rectangular or square.

13. A method for producing a single crystal wafer according to claim 10 or 11, wherein the other surface of the plate-like tray and at least a part of the bottom surface of the recess have a textured structure.

14. A method for producing a single crystal wafer according to claim 10 or 11, wherein the same substance is an inorganic substance.

15. The method for producing a single crystal wafer according to claim 14, wherein the inorganic material is a semiconductor.

16. The method for producing a single crystal wafer according to claim 15, wherein the semiconductor is germanium.

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