TWI593838B - Arrangement method of seed crystals and manufacturing method of monocrystalline-like ingot - Google Patents

Description

Method for laying seed crystals and method for producing single crystal ingot

The disclosure relates to a method for laying a seed crystal and a method for producing a single crystal ingot.

A solar cell is a photovoltaic element that generates electrical energy by absorbing sunlight and performing photoelectric conversion using a photovoltaic effect. At present, most of the materials of solar cells are mainly coffins, mainly because coffins are the second most easily available elements on the earth, and they have the advantages of low material cost, no toxicity, high stability, and the like. It has a solid foundation in the application of semiconductors.

At present, the most common application in germanium materials is crystalline germanium materials, including single crystal germanium and polycrystalline germanium. The single crystal germanium ingot is mainly a Czochralski method (CZ method) or a floating region method (floating zone method). The FZ method is prepared, and the polycrystalline germanium ingot is mainly prepared by a Directional Solidification method. Compared with the preparation method of single crystal germanium, the polycrystalline germanium ingot produced by the directional solidification method has a simple process and a production cost. It is widely used because of its low and large ingot size. Compared with the single crystal twin ingot, the polycrystalline germanium ingot has a low production cost, but a large number of grain boundaries and dislocation defects exist in the polycrystalline germanium ingot, so that the photoelectric conversion efficiency of the polycrystalline germanium solar cell is not as good as that of the single crystal germanium solar cell. Therefore, both production cost and photoelectric conversion efficiency have become important challenges in the development of polycrystalline silicon solar cells.

One embodiment of the present disclosure provides a method of laying a seed crystal comprising laying a spliced seed layer on the bottom of a long crystal container. The spliced seed layer comprises a plurality of single crystal blocks and a plurality of single crystal blocks, and the single crystal blocks are arranged at the bottom of the elongated crystal container and are not in contact with each other, and the single crystal blocking sheets are respectively sandwiched between adjacent single crystals. The gap between the blocks is respectively in contact with the adjacent single crystal block, and the width of the single crystal block is smaller than the width of the single crystal block. The crystal orientations of the single crystal blocks are the same and face the same direction. The main crystal orientation of the single crystal blank is the same as the main crystal orientation of the single crystal block, and the secondary crystal orientation of the single crystal blank and the secondary crystal orientation of the single crystal block. Each has an angle other than 0 degrees.

Another embodiment of the present disclosure provides a method for fabricating a single crystal-like ingot, comprising laying a spliced seed layer on the bottom of a long crystal container, forming a melt on the spliced seed layer, and cooling the melt so that The grains are grown from the spliced seed layer to form a type of single crystal ingot. The spliced seed layer comprises a plurality of single crystal blocks and a plurality of single crystal blocks, and the single crystal blocks are arranged at the bottom of the elongated crystal container and are not in contact with each other, and the single crystal blocking sheets are respectively sandwiched between adjacent single crystals. The gap between the blocks is respectively in contact with the adjacent single crystal block, and the width of the single crystal block is smaller than the width of the single crystal block. The crystal orientation of the single crystal block is the same and faces in the same direction. The main crystal orientation of the single crystal block and the main crystal of the single crystal block The same direction, and the minor crystal orientation of each of the single crystal blanks and the secondary crystal orientation of the single crystal block respectively have an angle of not more than 0 degrees.

The method of the present disclosure utilizes a spliced seed layer to produce a single crystal ingot, wherein the spliced seed layer comprises a single crystal block and a single crystal baffle, and the main crystal orientation of the single crystal baffle is the same as the main crystal orientation of the single crystal block but The minor crystal orientation of each of the single crystal blanks and the secondary crystal orientation of the single crystal block respectively have an angle of not more than 0 degrees, thereby suppressing generation of grain boundaries between the ingots grown by the adjacent single crystal blocks And dislocations, which in turn significantly reduce the defect area ratio.

10‧‧‧Long crystal container

12‧‧‧Splicing seed layer

12A‧‧‧ single crystal block

12B‧‧‧Single crystal blank

12B1‧‧‧Single film blank

12B2‧‧‧Single crystal blank

12G‧‧‧ gap

A‧‧‧ main crystal orientation

B1‧‧‧ secondary crystal orientation

B2‧‧‧ secondary crystal orientation

14‧‧‧ molten soup

16‧‧‧ class of single crystal ingots

V‧‧‧Long Crystal Direction

12C‧‧‧First peripheral blank

12D‧‧‧Second peripheral blank

12E‧‧‧ third peripheral flap

The aspects of the disclosure of the present application are best understood from the following detailed description and the accompanying drawings. Note that various features are not drawn to scale in accordance with standard implementations of the industry. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion.

1 to 4 illustrate a method of laying seed crystals according to an embodiment of the present disclosure.

4A is a schematic view showing the main crystal orientation and the secondary crystal orientation of the single crystal block of one embodiment of the present disclosure.

Figure 4B is a schematic view showing the main crystal orientation and the secondary crystal orientation of the single crystal blank of one embodiment of the present disclosure.

5 to 8 illustrate a method of fabricating a single crystal ingot such as an embodiment of the present disclosure.

Fig. 9 is a view showing a method of laying seed crystals according to a variant embodiment of the present disclosure.

10 to 13 illustrate a method of fabricating a single crystal ingot such as another embodiment of the present disclosure.

Fig. 14 is a view showing a method of laying seed crystals according to a variant embodiment of the present disclosure.

Fig. 15 is a view showing a method of laying a seed crystal according to still another embodiment of the present disclosure.

Fig. 16 is a graph showing the relationship between the defect area ratio and the height of the ingot of a single crystal twin ingot prepared in the examples and the comparative examples of the present disclosure.

Some embodiments of the present invention disclose a method for laying a seed crystal, comprising laying a spliced seed layer formed by combining a single crystal block and a single crystal baffle at the bottom of the elongated crystal container, wherein the single crystal block is configured to be located in the long crystal container The bottom portions are not in contact with each other, and the crystal orientations of the single crystal blocks are the same and face the same direction, and the single crystal blank is disposed in the gap between the adjacent single crystal blocks and is in contact with the adjacent single crystal blocks, and the single The width of the crystal stop sheet is smaller than the width of the single crystal block. The main crystal orientation of the single crystal blank is the same as the main crystal orientation of the single crystal block, but the secondary crystal orientation of the single crystal blank has an angle of not more than 0 degrees with the secondary crystal orientation of the single crystal block.

Other embodiments of the present invention disclose a method for fabricating a single crystal-like ingot, which uses the spliced single crystal seed layer to form a monocrystalline-like, or near-single-crystal, quasi-single Crystal) ingot. Further, the method of the present invention is to use a spliced single crystal germanium as a seed crystal, and use an ingot casting technique similar to a polycrystalline germanium ingot, such as a directional solidification method, to produce a single crystal ingot, so that the production cost and polycrystalline The production cost of the ingot is close, and the produced single crystal ingot has similar qualities and characteristics as the single crystal ingot. In the method of fabricating a single crystal ingot such as the present invention, the single crystal blocks of the spliced seed layer have the same crystal orientation (for example, {100} crystal In the same direction, the ingot grown from the single crystal block will also be a single crystal and its crystal orientation will be in the same direction. On the other hand, the main crystal orientation of the single crystal blank is the same as the main crystal orientation of the single crystal block, so that the ingot grown from the single crystal blank has the same growth rate as the ingot grown from the single crystal block. However, since the secondary crystal orientations of the two are oriented in different directions, the single crystal blank has the effect of suppressing the generation of grain boundaries and dislocations, and can reduce the number of defects in the crystal growth process, thereby improving the photoelectric conversion of the ingot. effectiveness. In short, the single crystal ingot prepared by the method of the present invention takes into account the low defects of the single crystal ingot, can be wet etched with an alkaline solution to form a roughened surface and a diamond cutting wire (diamond wire) The advantages of cutting and the low cost advantages of polycrystalline ingots can accelerate the development of solar cells.

Please refer to Figures 1 to 4. 1 to 4 illustrate a method for laying a seed crystal according to an embodiment of the present disclosure, wherein the first and third figures are shown in the above view, and the second figure is taken along the line 1 in the first figure. 1 is a schematic cross-sectional view, and FIG. 4 is a schematic cross-sectional view taken along line 2-2 of FIG. As shown in Figs. 1 and 2, a long crystal container 10 is first provided. The crystal growth vessel 10 may be a mold of tantalum or other heat resistant material such as quartz, graphite, tantalum nitride or tantalum carbide. The size (including the bottom area and height) and shape of the crystal growth vessel 10 can be adjusted depending on the size and shape of the ingot to be produced. In the present embodiment, the crystal growth vessel 10 is a square tank body which can be used to produce an ingot having a rectangular columnar body. In other embodiments, the elongated container 10 can have other shapes, such as a cylindrical trough or other geometric shaped trough.

As shown in Figures 3 and 4, a spliced seed layer 12 is then applied to the bottom of the elongated container 10, wherein the spliced seed layer 12 includes a plurality of single crystal blocks 12A and A plurality of single crystal blanks 12B. The single crystal block 12A is disposed at the bottom of the elongated crystal container 10, wherein the number, length, width, thickness, shape, and the like of the single crystal block 12A may depend on the bottom area of the crystal growth vessel 10, the preparation method of the single crystal block 12A, or Other factors are considered to adjust. In this embodiment, four square single crystal blocks having the same area are spliced into a 2*2 matrix pattern as an example, but not limited thereto. In other embodiments, other numbers or shapes of single crystal blocks may be spliced into any pattern, such as a 5*5 matrix pattern, a 6*6 matrix pattern, a circular pattern, or other pattern. In some embodiments, the single crystal block 12A can be obtained by cutting a single crystal cylinder made by a crystal pulling method or a floating region method, but is not limited thereto. The single crystal block 12A of the present embodiment has the same crystal orientation (for example, {100} crystal orientation), but is not limited thereto, and the single crystal block 12A is configured to be disposed at the bottom of the elongated crystal container 10 to make all The crystal orientation of the single crystal block 12A faces in the same direction. Further, the single crystal blocks 12A are not in contact with each other, that is, there is a gap 12G between the opposite side walls of any two adjacent single crystal blocks 12A. For example, the four single crystal blocks 12A of the present embodiment are laid at four corners of the bottom of the elongated crystal container 10, whereby a cross-shaped gap 12G exists between the single crystal blocks 12A.

On the other hand, the single crystal blank 12B is laid on the bottom of the elongated crystal container 10 such that the single crystal blanks 12B are respectively sandwiched between the gaps 12G between the adjacent single crystal blocks 12A and respectively adjacent to the adjacent single crystal blocks. 12A contact, wherein the number, length, width, thickness and shape of the single crystal baffle 12B may depend on the bottom area of the crystal growth vessel 10, the preparation mode of the single crystal baffle 12B, the shape and size of the single crystal block 12A, or other factors. Adjust with consideration. Corresponding to the arrangement of the single crystal block 12A, in this embodiment, four rectangular single crystal blanks 12B are respectively interposed in the gap 12G between the adjacent single crystal blocks 12A, but not Limited. In some embodiments, the single crystal blank 12B can be obtained by cutting a single crystal cylinder made by a crystal pulling method or a floating region method, whereby the single crystal blank 12B and the single crystal block 12A have the same main crystal. The process of cutting the single crystal cylinders in different directions may cause the single crystal blank 12B and the single crystal block 12A to have different secondary crystal orientations. Please refer to Figures 4A and 4B. 4A is a schematic view showing a main crystal orientation and a secondary crystal orientation of a single crystal block according to an embodiment of the present disclosure, and FIG. 4B is a view showing a main crystal orientation and a secondary crystal of a single crystal blank according to an embodiment of the present disclosure. Schematic diagram of the direction. As shown in FIGS. 4A and 4B, the single crystal block 12A and the single crystal blank 12B can be obtained by cutting the same single crystal cylinder, so that the single crystal block 12A and the single crystal blank 12B have the same main crystal orientation A. And cutting the single crystal cylinder in different directions may cause the single crystal block 12A to have a secondary crystal orientation B1 and the single crystal blank 12B to have a secondary crystal orientation B2. In some embodiments, the single crystal blank 12B is obtained by diamond wire cutting, wherein the wire cutting slice angle is preferably between 1 and 40 degrees, and more preferably between 10 and 30 degrees, for example. 10 degrees, 20 degrees or 30 degrees, but not limited to this. Therefore, the angle between the minor crystal orientation of the single crystal sheet 12B and the minor crystal orientation B1 of the single crystal block 12A is preferably between 1 and 40 degrees, and more preferably between 10 and 30 degrees, but not This is limited to this. In the method of the present invention, as long as the minor crystal grain of the single crystal piece 12B and the minor crystal grain of the single crystal piece 12A are not 0 degrees, the adjacent single crystal block 12A can be suppressed. Grain boundaries and dislocations occur between the ingots that grow. In addition, it is worth noting that the secondary crystal grain of the single crystal piece 12B and the minor crystal of the single crystal piece 12A are substantially the same angle of 0 degree or 90 degree to the B1, that is, the single crystal file. The minor crystal orientation of the sheet 12B and the minor crystal orientation of the single crystal block 12A to the B1 are between 0 and 45 degrees, which is substantially equal to the secondary crystal orientation B2 and the single crystal of the single crystal sheet 12B. The minor angle of the block 12A to B1 is between 45 and 90 degrees. In some embodiments, the larger-area single crystal block 12A may be first laid on the bottom of the elongated crystal container 10, and the smaller single-crystal blank 12B is filled into the gap 12G between the single crystal blocks 12A, but Not limited to this. In other embodiments, the single crystal baffle 12B may be first laid on the bottom of the crystal growth vessel 10, and then the single crystal block 12A may be laid on the bottom of the crystal growth vessel 10; or, the single crystal block 12A and the single crystal may be first The crystal stop sheets 12B are combined into a spliced seed layer 12 and simultaneously laid on the bottom of the elongated crystal container 10.

In some embodiments, the secondary crystal orientations of the different single crystal blanks 12B may be laid in different directions, that is, the different single crystal blanks 12B may have different secondary crystal orientations from the single crystal bulk 12A. The angles of the adjacent single crystal blanks 12B are also oriented in different directions, whereby the ingots grown by the positions corresponding to the adjacent single crystal blanks 12B are also different in direction of the crystal orientation. The grain boundaries and dislocations are suppressed, thereby reducing the number of defects in the crystal growth process.

In some embodiments, the material of the single crystal block 12A and the single crystal blank 12B is germanium, but not limited thereto.

Please refer to Figures 5 to 8 for the first to fourth figures. 5 to 8 illustrate a method of fabricating a monocrystalline-like ingot according to an embodiment of the present disclosure, wherein the fifth and seventh figures are shown in the above view, and the sixth figure is along the line. Fig. 5 is a schematic cross-sectional view taken along line 3-3 of Fig. 5, and Fig. 8 is a schematic cross-sectional view taken along line 4-4 of Fig. 7. As shown in FIGS. 5 and 6, after the spliced seed layer 12 is laid on the bottom of the elongated container 10, a melt 14 is formed on the spliced seed layer 12. In this embodiment, a method for manufacturing a single crystal germanium is taken as an example, and thus the seed layer 12 is spliced. The material used is enamel, and the material of fused soup 14 is also 矽. In the present embodiment, the melt 14 can be formed in the following manner. The tantalum raw material is placed in the growth vessel 10 and stacked on the surface of the spliced seed layer 12. Thereafter, the crystal growth vessel 10 containing the niobium material is placed in a directional solidification system crystal growth furnace or other crystal growth apparatus and the crucible material is heated to melt into the melt soup 14. In other embodiments, the crucible material may be first melted into melt 14 and the melt 14 poured into the growth vessel 10.

As shown in Figs. 7 and 8, the directional solidification process is followed by cooling the melt 14 so that the crystal grains gradually grow in a crystal growth direction V to form a single crystal-like crystal ingot 16. In the present embodiment, since the single crystal blank 12B and the single crystal block 12A have the same crystal orientation by the splicing of the seed layer 12, the crystal grown from the single crystal blank 12B along the crystal growth direction V The ingot in which the ingot and the single crystal block 12A grow in the crystal growth direction V has an approximate growth rate, and since the secondary crystal orientation of both the single crystal blank 12B and the single crystal block 12A faces in different directions, The ingot grown from the single crystal blank 12B can suppress the occurrence of grain boundaries and dislocations between the ingots grown by the single crystal block 12A located on both sides thereof, thereby reducing the number of defects in the crystal growth process.

Further, since the secondary crystal orientation of the ingot grown by the single crystal stopper 12B faces the secondary crystal orientation of the ingot grown by the single crystal block 12A in different directions, the appearance of the ingot still causes inconsistency. Visual effects. Therefore, when designing the pattern of the spliced seed layer 12, the width of the single crystal slab 12B is smaller than the width of the single crystal block 12A, whereby the single crystal slab 12B can provide the effect of suppressing grain boundaries and dislocations, but not for The appearance of the single crystal ingot 16 has a significant effect. For example, the width of the single crystal blank 12B is between about 0.5 mm and 4 mm, and the width of the single crystal block 12A is about 142 mm. Between 155.5mm, but not limited to this. In some embodiments, the ratio of the width of the single crystal blank 12B to the width of the single crystal block 12A is substantially between 0.32% and 2.82%, and preferably between 0.65% and 2.46%. Take into account the function and appearance consistency of reducing defects. In some embodiments, the area of the single crystal blank 12B is between about 2% and 20% of the area of the bottom of the crystal growth vessel 10, and preferably between 2.3% and 15.02%, but not limited thereto.

The single crystal ingot 16 of this embodiment can be further cut into a crystal-like crystal brick and a single crystal-like wafer, and further used as a substrate for a solar cell or other photovoltaic element. The single crystal-like ingot 16 produced by the method of the present embodiment has a low defect advantage similar to that of a single crystal ingot, so that the produced solar cell can have high photoelectric conversion efficiency. Further, the single crystal ingot 16 of the present embodiment is formed by an ingot forming method similar to a polycrystalline germanium ingot, and has an advantage of low manufacturing cost and cutting by a diamond wire. In addition, in order to increase the light utilization efficiency, the surface of the solar cell may be roughened, and the single crystal ingot 16 of the present embodiment is cut out compared to a polycrystalline ingot which must be formed by a dry etching method to form a roughened surface. The single crystal-like wafer can be wet etched using an alkaline solution to form a roughened surface, which further reduces the cost.

In some embodiments, the arrangement of the single crystal blank 12B may have the effect of increasing aesthetics and display information in addition to inhibiting the effect of grain boundaries and dislocations between the grown ingots. Further, since the secondary crystal grain 12B secondary crystal orientation and the single crystal block 12A minor crystal orientation are oriented in different directions so that the two are different in the appearance of the ingot, if the single crystal block 12A and the single crystal block are transmitted through The pattern design of the piece 12B can make The crystal grains of the single crystal-like ingot 16 to be produced have a predetermined arrangement rule, whereby the prepared wafer can exhibit a predetermined pattern or text after being etched by the alkaline solution, thereby increasing the application range of the solar cell. .

The different embodiments of the present invention are described below, and in order to simplify the description, the following description is mainly directed to the differences of the embodiments, and the details are not repeated. In addition, the same elements in the embodiments of the present invention are denoted by the same reference numerals to facilitate the comparison between the embodiments.

Please refer to Figure 9. Fig. 9 is a view showing a method of laying seed crystals according to a variant embodiment of the present disclosure. As shown in FIG. 9, unlike the foregoing embodiment, in the spliced seed layer 12 of the present embodiment, two or more single crystal blanks are laid in the gap 12G between two adjacent single crystal blocks 12A. 12B1, 12B2, wherein the single crystal blanks 12B1, 12B2 may be adjacent to each other and in contact, and may have the same or different secondary crystal orientations.

Please refer to Figures 10 to 13. 10 to 13 illustrate a method of fabricating a single crystal ingot according to another embodiment of the present disclosure, wherein the 10th and 12th drawings are shown in the above view, and the 11th is along the 10th. A cross-sectional view taken along line 5-5, and a thirteenth view is a cross-sectional view taken along line 6-6 of Fig. 12. As shown in FIGS. 10 and 11, in addition to the foregoing embodiment, the spliced seed layer 12 of the present embodiment further includes a first peripheral dam 12C in addition to the single crystal block 12A and the single crystal blank 12B. The second peripheral flap 12D. The first peripheral flap 12C is laid at the bottom of the elongated container 10 and located between the inner wall of the elongated container 10 and the single crystal block 12A, and the second peripheral blank 12D is laid at the bottom of the elongated container 10 and located in the elongated crystal. The inner wall of the container 10 is between the first peripheral flap 12C.

The first peripheral blocking piece 12C may be an annular blocking piece (for example, a hollow rectangular ring) surrounding the single crystal block 12A and the single crystal blocking piece 12B, or composed of a plurality of straight strip-shaped blocking pieces and surrounding the single crystal block 12A and the single The crystal piece 12B. In some embodiments, the first peripheral blank 12C is a single crystal structure, such as a single crystal germanium, and the main crystal orientation of the first peripheral blank 12C is the same as the main crystal orientation of the single crystal bulk 12A (for example, {100} crystal orientation ), but not limited to this. In addition, the secondary crystal orientation of the first peripheral blank 12C faces the secondary crystal orientation of the single crystal block 12A in a different direction, that is, the secondary crystal orientation of the first peripheral blank 12C and the secondary crystal of the single crystal block 12A. The direction has a second angle, wherein the second angle is preferably between 1 and 40 degrees, for example, the second angle is 20 degrees, but not limited thereto.

The second peripheral flap 12D may be an annular flap (for example, a hollow rectangular ring) surrounding the first peripheral flap 12C or composed of a plurality of straight strips and surrounding the first peripheral flap 12C. In some embodiments, the second peripheral blank 12D is a single crystal structure, such as a single crystal germanium, whose main crystal orientation is the same as the main crystal orientation of the single crystal block 12A (for example, {100} crystal orientation), but is not limit. In addition, the secondary crystal orientation of the second peripheral flap 12D faces the secondary crystal orientation of the first peripheral flap 12C in a different direction, that is, the secondary crystal orientation of the second peripheral flap 12D and the first peripheral flap 12C. The secondary crystal orientation has a third angle, and the third angle is, for example, 36.8 degrees, but is not limited thereto.

As shown in Fig. 12 and Fig. 13, the melt is then formed on the spliced seed layer 12 and the directional solidification process is used to carry out the directional solidification process to cool the melt so that the crystal grains gradually grow along the crystal growth direction V. A single crystal ingot 16 is formed.

In this embodiment, the spliced seed layer 12 is formed by splicing the single crystal block 12A and the single crystal baffle 12B, the first outer baffle 12C and the second outer baffle 12D. The configuration of the medium single crystal block 12A and the single crystal blank 12B and the effects thereof provided in the crystal growth process are the same as those of the foregoing embodiment, and will not be described herein. In the present embodiment, the first peripheral flap 12C and the second peripheral flap 12D are configured to suppress defects caused by the inner wall of the crystal growth vessel 10 during the growth process. Further, the second peripheral blank 12D is located between the inner wall of the elongated container 10 and the first peripheral blank 12C, and thus is grown by the second peripheral blank 12D along the crystal growth direction V during the growth process. The ingot will have more defects. The first peripheral blocking piece 12C disposed between the second peripheral blocking piece 12D and the single crystal block 12A can prevent the defect in the ingot growing in the crystal growth direction V of the second peripheral blocking piece 12D from growing inwardly and affecting the single The ingot grown in the crystal growth direction V of the ingot 12A ensures the quality of the ingot grown in the crystal growth direction V of the single crystal block 12A. In order to achieve the above-mentioned blocking defect, the secondary crystal orientation of the second peripheral blank 12D of the present embodiment has a third angle with the secondary crystal orientation of the first peripheral blank 12C, wherein the third included angle can be according to the second peripheral The crystal orientation of the sheet 12D is adjusted to the secondary crystal orientation of the first peripheral flap 12C. For example, when the main crystal orientation of the second peripheral flap 12D and the main crystal orientation of the first peripheral flap 12C are {100} crystal orientation, the third angle may be selected to be 36.8 degrees, but not limited thereto.

The spliced seed layer 12 of the present embodiment includes a single crystal block 12A and a single crystal baffle 12B, a first peripheral baffle 12C and a second peripheral baffle 12D, wherein the single crystal baffle 12B is used to suppress adjacent single crystals Grain boundaries and dislocations are generated between the ingots grown in block 12A to reduce the number of defects in the crystal growth process, and the first peripheral blank 12C and the second peripheral blank 12D are used to block the growth process. The defect caused by the inner wall of the crystal growth vessel 10 extends inwardly to the single crystal block 12A, whereby the method of the embodiment can be fabricated It has a good quality single crystal ingot.

Please refer to Figure 14. Fig. 14 is a view showing a method of laying seed crystals according to a variant embodiment of the present disclosure. As shown in FIG. 14, unlike the embodiment of FIGS. 10 to 13, the spliced seed layer 12 of the present embodiment is identical to the single crystal block 12A and the single crystal block 12B, the first peripheral cover 12C and the second. In addition to the peripheral flap 12D, a third peripheral flap 12E is further disposed between the first peripheral flap 12C and the second peripheral flap 12D. The third peripheral flap 12E may be an annular flap (for example, a hollow rectangular ring) or a plurality of straight strips. In some embodiments, the third peripheral blank 12E is a single crystal structure, such as a single crystal germanium, whose main crystal orientation is the same as the main crystal orientation of the single crystal block 12A (for example, {100} crystal orientation), but is not limit. In addition, the secondary crystal orientation of the third peripheral flap 12E faces the secondary crystal orientation of the first peripheral flap 12C in a different direction, that is, the secondary crystal orientation of the third peripheral flap 12E and the first peripheral flap 12C. The secondary crystal orientation has a fourth angle, and the fourth angle is, for example, 36.8 degrees, but is not limited thereto.

Please refer to Figure 15. Fig. 15 is a view showing a method of laying a seed crystal according to still another embodiment of the present disclosure. As shown in Fig. 15, unlike the foregoing embodiment, the crystal growth vessel 10 of the present embodiment is a cylindrical tank body, and the spliced seed layer 12 is a circular pattern. The spliced seed layer 12 includes four fan-shaped single crystal blocks 12A laid at the bottom of the circular elongated crystal container 10, and four rectangular single crystal blanks 12B are respectively sandwiched between two adjacent single crystal blocks 12A, one The first annular outer peripheral flap 12C is located between the inner wall of the elongated crystal container 10 and the single crystal block 12A, and a second outer peripheral flap 12D is located at the inner wall of the elongated crystal container 10 and the first outer peripheral flap 12C. between.

The main crystal orientation of the single crystal blank 12B and the main crystal orientation of the single crystal block 12A Similarly, for example, the main crystal orientations of both the single crystal blank 12B and the single crystal bulk 12A are both {100} crystal orientation, and the secondary crystal orientation of each of the single crystal blanks 12B and the secondary crystal orientation of the single crystal bulk 12A are respectively different. It has an angle of not more than 0 degrees. In some embodiments, the angle between the minor crystal grains of the single crystal blank 12B and the single crystal block 12A is between 1 and 40 degrees, and preferably between 10 and 30 degrees, but not This is limited. The main crystal orientation of the first peripheral blank 12C is the same as the main crystal orientation of the single crystal block 12A (for example, {100} crystal orientation), but is not limited thereto. Further, the secondary crystal orientation of the peripheral blank 12C faces the secondary crystal orientation of the single crystal block 12A in a different direction, that is, the secondary crystal orientation of the first peripheral blank 12C and the secondary crystal orientation of the single crystal block 12A have a second angle, and the second angle is between 1 and 40 degrees, for example, the second angle is 20 degrees, but not limited thereto. In some embodiments, the second peripheral blank 12D is a single crystal structure, such as a single crystal germanium, whose main crystal orientation is the same as the main crystal orientation of the single crystal block 12A (for example, {100} crystal orientation), but is not limit. In addition, the secondary crystal orientation of the second peripheral flap 12D faces the secondary crystal orientation of the first peripheral flap 12C in a different direction, that is, the secondary crystal orientation of the second peripheral flap 12D and the first peripheral flap 12C. The secondary crystal orientation has a third angle, and the third angle is, for example, 36.8 degrees, but is not limited thereto. The spliced seed layer 12 of the present embodiment can be used to produce a single crystal-like ingot by the foregoing ingot casting method. The detailed process is disclosed in the foregoing embodiment, and details are not described herein again.

Please refer to Figure 16. Figure 16 is a graph showing the relationship between the defect area ratio and the height of the ingot of the single crystal twin ingot prepared by the embodiment of the present disclosure and the comparative example, wherein the samples 2 and 3 are made in the embodiment of the disclosure. A crystal ingot comprising a single crystal block and a single crystal blank as a spliced seed layer; Sample 1 is a comparative example to produce a single crystal twin ingot, which does not contain a single crystal block and a single crystal blank. As a splicing seed Floor. Please refer to Table 1, Table 2 and Table 3 together. Table 1 shows the measurement results of the defect area distribution of a single crystal twin ingot produced by the method of a comparative example (Sample 1), and Table 2 and Table 3 show two examples of the present disclosure (Sample 2) And the method of sample 3) produces a measurement result of the defect area distribution of a single crystal twin ingot.

As shown in Table 1, the defect area ratios of the single crystal twin ingots such as the comparative example (sample 1) at positions of 38 mm, 84.9 mm, 125.6 mm, and 250 mm were 0.567%, 2.40%, 7.98%, and 24.6%, respectively. That is to say, at a height of 84.9 mm, the defect area ratio of the single crystal twin ingot is 4.23 times higher than that at the height of 38 mm, and the single crystal twin ingot is at a height of 125.6 mm. The defect area ratio was increased by 14.07 times, and at a height of 250 mm, the defect area ratio of the single crystal twin ingot was increased by 43.39 times. Therefore, the defect area ratio of the single crystal twin ingot produced in the method of the comparative example was significantly increased in multiples in the crystal growth direction.

table 3

As shown in Table 2, the defect area ratio of the single crystal twin ingot of the sample 2 of the present embodiment at positions of 38 mm, 84.9 mm, and 125.6 mm in height was 0.141%, 0.409%, and 1.206%, respectively, that is, Based on the position of 38 mm in height, the defect area ratio of the single crystal twin ingot grows only 2.90 times at a height of 84.9 mm, and the defect area of the single crystal twin ingot at a height of 125.6 mm. It grew by 8.55 times. As shown in Table 3, the defect area ratio of the single crystal twin ingot of the sample 3 of the present embodiment at positions of heights of 50.4 mm, 87.9 mm, 125.4 mm, 162.9 mm, 200.4 mm, and 240.5 mm, respectively, was 0.149%. 0.398%, 0.241%, 0.324%, 0.455%, and 1.385%, that is, the defect area ratio of the single crystal twin ingot grew by only 2.67 at a height of 87.9 mm. At a height of 125.4 mm, the defect area ratio of the single crystal twin ingot is only 1.61 times, and at a height of 162.9 mm, the defect area ratio of the single crystal twin ingot is only 2.17 times. At a height of 200.4 mm, the defect-area ratio of the single crystal-like germanium ingot is only 3.05 times higher, and at a height of 240.5 mm, the single crystal twin ingot is ingot. The defect area ratio grew by 9.29 times. Therefore, compared with the comparative example (sample 1), the method of the present example (sample 2 and sample 3) produced a single crystal twin ingot, and the defect area growth in the crystal growth direction was significantly slower, showing a single crystal. Blocks, single crystal blanks and peripheral blanks can effectively suppress the growth of defective areas.

The method of the present disclosure utilizes a spliced seed layer to produce a single crystal ingot, wherein the spliced seed layer comprises a single crystal block and a single crystal baffle, and the main crystal orientation of the single crystal baffle is the same as the main crystal orientation of the single crystal block but The minor crystal orientation of each of the single crystal blanks and the secondary crystal orientation of the single crystal block respectively have an angle of not more than 0 degrees, thereby suppressing generation of grain boundaries between the ingots grown by the adjacent single crystal blocks And dislocations, which in turn significantly reduce the defect area ratio. Additionally, the spliced seed layer may further include a peripheral baffle to block inwardly extending defects caused by the inner wall of the crystal growth vessel during the growth process.

In summary, the single crystal ingot produced by the method of the present embodiment has both the low defect advantage of the single crystal ingot and the low manufacturing cost advantage of the polycrystalline ingot. In addition, compared with the polycrystalline ingot, the single crystal ingot prepared by the method of the present embodiment can be cut by using a diamond cutting line and wet etching by using an alkaline solution to form a roughened surface, and further can be further cut costs. Furthermore, the crystal grains of the single-crystal-like crystal ingot produced by the method of the present embodiment have a predetermined arrangement rule, whereby the prepared single crystal-like wafer can exhibit a predetermined pattern or text after being etched by the alkaline solution. , can increase the range of applications of solar cells.

10‧‧‧Long crystal container

12‧‧‧Splicing seed layer

12A‧‧‧ single crystal block

12B‧‧‧Single crystal blank

12C‧‧‧First peripheral blank

12D‧‧‧Second peripheral blank

Claims (24)

A method for laying a seed crystal, comprising: laying a spliced seed layer on a bottom of a long crystal container, wherein the spliced seed layer comprises a plurality of single crystal blocks and a plurality of single crystal blocks, the single crystal blocks being configured Located at the bottom of the crystal growth vessel and not in contact with each other, the single crystal blanks are respectively sandwiched between the adjacent spaces of the single crystal blocks and respectively contacted with at least one of the adjacent single crystal blocks. The width of the single crystal block is smaller than the width of the single crystal block, and the crystal directions of the single crystal blocks are the same and face the same direction, and the main crystal orientation of the single crystal blocks and the main crystal orientation of the single crystal blocks The same, and the minor crystal orientation of each of the single crystal blanks and the secondary crystal orientation of the single crystal blocks respectively have an angle of not more than 0 degrees. The laying method according to claim 1, wherein an angle between a minor crystal orientation of each of the single crystal blanks and a minor crystal orientation of the single crystal blocks is between 1 and 40 degrees. The laying method according to claim 1, wherein the main crystal orientation of the single crystal block and the single crystal blank is {100}. The laying method according to claim 1, wherein the material of the single crystal block and the single crystal blank comprises ruthenium. The laying method according to claim 1, wherein a ratio of a width of the single crystal block to a width of the single crystal block is between 0.32% and 2.82%. The laying method according to claim 1, wherein the single crystal blank has a width of between 0.5 mm and 4 mm. The laying method according to the first aspect of the patent application, wherein the single crystal blank The ratio of the area to the bottom area of the crystal growth vessel is between 2% and 20%. The laying method according to claim 1, wherein two or more of the single crystal blanks are laid in a gap between two adjacent ones of the single crystal blocks. According to the laying method of claim 1, wherein the splicing seed layer further comprises: a first peripheral baffle laid on the bottom of the crystal growth vessel and located on the inner wall of the crystal growth vessel and the single crystal Between the blocks; and a second peripheral flap disposed at the bottom of the elongated container and between the inner wall of the elongated container and the first peripheral flap. The laying method according to claim 9, wherein the first peripheral baffle is a single crystal structure, the main crystal orientation of which is the same as the main crystal orientation of the single crystal blocks, and the second peripheral baffle is secondary The crystal orientation has a second angle with the minor crystal orientation of the single crystal blocks, and the second angle is between 1 and 40 degrees. The laying method according to claim 9, wherein the second peripheral baffle is a single crystal structure whose main crystal orientation is the same as the main crystal orientation of the single crystal blocks, and the second peripheral baffle is secondary. The crystal orientation has a third angle with the minor crystal orientation of the first peripheral flap, and the third angle is 36.8 degrees. The splicing seed layer further includes a third peripheral lining disposed between the first peripheral lining and the second peripheral lining, the third periphery The baffle is a single crystal structure, the main crystal orientation of which is the same as the main crystal orientation of the single crystal blocks, and the minor crystal orientation of the third peripheral baffle has a fourth with the secondary crystal orientation of the first peripheral baffle The angle is included, and the fourth angle is 36.8 degrees. A method for fabricating a monocrystalline-like ingot comprises: laying a spliced seed layer on a bottom of a long crystal container, wherein the spliced seed layer comprises a plurality of single crystal blocks and a plurality of single crystal blanks The single crystal blocks are disposed at the bottom of the crystal growth vessel and are not in contact with each other. The single crystal blanks are respectively sandwiched between the adjacent spaces of the single crystal blocks and respectively adjacent to each other. The single crystal block contacts, the width of the single crystal block is smaller than the width of the single crystal block, the crystal directions of the single crystal blocks are the same and face the same direction, the main crystal orientation of the single crystal blocks and the single The main crystal orientations of the ingots are the same, and the minor crystal orientations of the single crystal blanks and the minor crystal orientations of the single crystal blocks respectively have an angle of not more than 0 degrees; forming a molten soup in the splice seed crystal And cooling the melt to grow crystal grains from the spliced seed layer to form a type of single crystal ingot. The manufacturing method according to claim 13, wherein an angle between a minor crystal orientation of each of the single crystal blanks and a minor crystal orientation of the single crystal blocks is between 1 and 40 degrees. The manufacturing method according to claim 13, wherein the main crystal orientation of the single crystal block and the single crystal blank is {100}. The manufacturing method according to claim 13, wherein the material of the single crystal block and the single crystal blank includes ruthenium. The manufacturing method according to claim 13, wherein a ratio of a width of the single crystal blank to a width of the single crystal block is between 0.32% and 2.82%. The manufacturing method according to claim 13, wherein the single crystal blank has a width of between 0.5 mm and 4 mm. The manufacturing method according to claim 13, wherein a ratio of an area of the single crystal baffle to a bottom area of the crystal growth vessel is between 2% and 20%. The manufacturing method according to claim 13, wherein two or more of the single crystal blanks are laid in a gap between two adjacent ones of the single crystal blocks. According to the manufacturing method of claim 13, wherein the splicing seed layer further comprises: a first outer lining is laid on the bottom of the crystal growth vessel and located on the inner wall of the crystal growth vessel and the single crystal Between the blocks; and a second peripheral flap disposed at the bottom of the elongated container and between the inner wall of the elongated container and the first peripheral flap. The manufacturing method according to claim 21, wherein the first peripheral baffle is a single crystal structure whose main crystal orientation is the same as the main crystal orientation of the single crystal blocks, and the first peripheral baffle is secondary. The crystal orientation has a second angle with the minor crystal orientation of the single crystal blocks, and the second angle is between 1 and 40 degrees. The manufacturing method according to claim 21, wherein the second peripheral baffle is a single crystal structure whose main crystal orientation is the same as the main crystal orientation of the single crystal blocks, and the second peripheral baffle is secondary. The crystal orientation has a third angle with the minor crystal orientation of the first peripheral flap, and the third angle is 36.8 degrees. The manufacturing method of claim 21, wherein the splicing seed layer further comprises a third outer lining disposed between the first outer lining and the second outer lining, the third outer periphery The baffle is a single crystal structure, the main crystal orientation of which is the same as the main crystal orientation of the single crystal blocks, and the secondary crystal orientation of the third peripheral baffle The minor orientation of the first peripheral flap has a fourth angle, and the fourth angle is 36.8 degrees.