Substrate and semiconductor device

Abstract

The utility model relates to the technical field of semiconductor manufacturing, in particular to a substrate and a semiconductor device. The substrate is provided with a growth surface, and an epitaxial growth region is formed on at least part of the surface of the growth surface; the epitaxial growth region is provided with a flat region, a convex region and a concave region; the flat region is a horizontal surface located on the epitaxial growth region; the convex region protrudes from the flat region to the direction far away from the substrate, and the concave region sinks from the flat region to the interior of the substrate; the plurality of convex regions are positioned on the edge close to the epitaxial growth region; the at least one recessed region is closer to the center of the epitaxial growth region than the raised region. By designing the concave regions and the convex regions at different positions of the substrate, the uniformity of the epitaxial wavelength can be effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor, especially a kind of substrate and semiconductor device. BACKGROUND

[0002] At present, the traditional substrate processing is generally through line cutting, grinding, annealing, chamfering, copper throwing and polishing etc. steps, to realize the planarization of substrate surface, for subsequent growth epitaxial structure. Usually, in order to the uniformity of subsequent yellow light and epitaxial wafer, the thickness difference and warpage of substrate need to be small enough.

[0003] And in the process of the planarization of substrate surface designed according to the prior art, the substrate rotates at high speed in graphite carrier tray, the corresponding airflow exists windward side and leeward side, which is prone to the problem of poor symmetry uniformity of epitaxial wavelength. Therefore, how to improve the uniformity of epitaxial wavelength is still a difficult problem to be solved by the technical personnel at present. SUMMARY

[0004] The utility model provides a kind of substrate and semiconductor device, can solve at least one problem in the background art to effectively improve the symmetry uniformity of epitaxial wavelength.

[0005] In the first aspect, the utility model provides a kind of substrate, the substrate has growth surface, at least part of surface of the growth surface is formed with epitaxial growth area;The epitaxial growth area has flat area, convex area and recessed area;The flat area is horizontal surface located on the epitaxial growth area;The convex area is raised from the flat area to the direction away from the substrate, and the recessed area is recessed from the flat area to the interior of the substrate;A plurality of convex areas are located close to the edge of the epitaxial growth area;At least one recessed area is closer to the center of the epitaxial growth area relative to the convex area.

[0006] In the second aspect, the utility model further provides a kind of semiconductor device, uses the substrate of above embodiment.

[0007] The substrate provided by the utility model can effectively improve the symmetry uniformity of epitaxial wavelength on the substrate by designing the recessed area and convex area at different positions of the substrate, and further improve the performance of epitaxial structure when the substrate is applied to epitaxial growth.

[0008] Other features and advantages of the utility model will be set forth in the subsequent specification, and some become apparent from the specification, or be understood by implementing the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0010] Figure 1 is a schematic diagram of the epitaxial wavelength distribution on the conventional substrate;

[0011] Figure 2 is a schematic diagram of the epitaxial growth process structure of the conventional substrate on the base;

[0012] Figure 3 is a schematic diagram of the epitaxial growth process structure of the substrate of the first embodiment on the base;

[0013] Figure 4 , Figure 5 is a cross-sectional view of the substrate of each embodiment provided by the first embodiment of the present application;

[0014] Figures 6-8 is a top view structural schematic diagram of the substrate of each embodiment provided by the first embodiment of the present application;

[0015] Figure 9 is a schematic diagram of the epitaxial wavelength distribution on the substrate of the present embodiment.

[0016] Reference signs:

[0017] 10-epitaxial growth region; 11-flat area; 12-protruding area; 13-recessed area; S1-growth surface; 12a-first protruding area; 12b-second protruding area; 12c-third protruding area. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. The technical features designed in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0019] It should also be noted that the structural schematic diagram provided by the present application is to more clearly express the structural features of the substrate, but is not made in proportion.

[0020] The utility model provides a kind of substrate, the substrate has growth surface, at least part surface of the growth surface is formed with epitaxial growth area;The epitaxial growth area has flat area, convex area and recessed area;The flat area is horizontal surface located on the epitaxial growth area;The convex area is protruded from the flat area to the direction away from the substrate, and the recessed area is recessed from the flat area to the inside of the substrate;Several convex areas are located close to the edge of the epitaxial growth area;At least one recessed area is closer to the center of the epitaxial growth area relative to the convex area.By the setting, the symmetry uniformity of epitaxial wavelength on substrate can be effectively improved.

[0021] In some embodiments, the thickness of the substrate at the flat area position is H, and the height h1 from the highest point of the convex area away from the substrate to the flat area of the substrate is between 0.1%H and 2%H, to avoid the height of the convex area being too small to achieve the purpose of good uniform epitaxial wavelength, or the height being too large to affect the quality of epitaxial growth.

[0022] In some embodiments, the thickness of the substrate at the flat area position is H, and the height h2 from the lowest point of the recessed area recessed to the inside of the substrate to the flat area of the substrate is between 0.1%H and 2%H, to also avoid the height of the recessed area being too small to achieve the purpose of good uniform epitaxial wavelength, or the height being too large to affect the quality of epitaxial growth.

[0023] In some embodiments, the projection direction perpendicular to the flat area of the substrate is defined as orthographic projection, and the total area of the orthographic projection of the several convex areas on the growth surface is greater than the total area of the orthographic projection of the recessed area on the surface. Through the above setting, the epitaxial wavelength can be better uniform.

[0024] In some embodiments, the projection direction perpendicular to the flat area of the substrate is defined as orthographic projection, and the total area of the orthographic projection of the flat area on the growth surface is greater than the total area of the orthographic projection of the recessed area on the growth surface, to ensure the quality of epitaxial growth and avoid the recessed area being too large to affect the epitaxial growth.

[0025] In some embodiments, the epitaxial growth area has a shortest width W, and the recessed area is located within a range of 0.4W offset from the geometric center point of the epitaxial growth area in at least one horizontal direction; and the convex area is located outside the range of 0.4W offset from the geometric center point of the epitaxial growth area in at least one horizontal direction. By limiting the position of the recessed area and the convex area, the difference in epitaxial wavelength can be effectively improved.

[0026] In some embodiments, the included angle α between the tangent line of the outer contour of the convex area and the geometric center point of the epitaxial growth area is between 50° and 100°.

[0027] In some embodiments, an angle β formed between the outer contours of the adjacent convex regions at a geometric center point of the epitaxial growth region is greater than or equal to 20°. By limiting the angle of the convex regions as described above, the epitaxial wavelength can be effectively and uniformly controlled.

[0028] In some embodiments, the convex regions include a first convex region, a second convex region, and a third convex region; an angle α1 between a tangent line of the outer contour of the first convex region and the geometric center point of the epitaxial growth region is between 50° and 70°; an angle α2 between a tangent line of the outer contour of the second convex region and the geometric center point of the epitaxial growth region is between 50° and 70°; and an angle α3 between a tangent line of the outer contour of the third convex region and the geometric center point of the epitaxial growth region is between 80° and 100°.

[0029] In some embodiments, the geometric center point of the concave region is closer to a region between the first convex region and the third convex region, or the geometric center point of the concave region is closer to a region between the second convex region and the third convex region, compared to the geometric center point of the epitaxial growth region.

[0030] In some embodiments, an angle β1 formed between the outer contours of the first convex region and the second convex region at the geometric center point of the epitaxial growth region is between 50° and 70°, an angle β2 formed between the outer contours of the second convex region and the third convex region at the geometric center point of the epitaxial growth region is between 20° and 40°, and an angle β3 formed between the outer contours of the third convex region and the first convex region at the geometric center point of the epitaxial growth region is between 50° and 70°. This arrangement not only achieves the effect of uniform epitaxial wavelength, but also ensures the quality of epitaxial growth.

[0031] In some embodiments, the convex regions and the concave regions are formed by a laser hidden cutting process.

[0032] The utility model also provides a kind of semiconductor device, it is characterized by: including the substrate using any one embodiment as described above, further include epitaxial layer, the epitaxial layer is located on the epitaxial growth region of the substrate, to improve the symmetry uniformity of epitaxial luminescence wavelength of semiconductor device.

[0033] In some embodiments, the standard deviation of the luminescence wavelength of the epitaxial layer located on the epitaxial growth region is between 0.5 and 1 nm.

[0034] In some embodiments, the standard deviation of the luminescence wavelength of the epitaxial layer located on the epitaxial growth region is less than or equal to 0.5 nm.

[0035] Next, the technical solutions of the present application will be described and explained in detail through various specific embodiments in combination with the accompanying drawings.

[0036] Embodiment one

[0037] Please refer to Figure 4 、 Figure 5 , Figure 4 、 Figure 5 is a cross-sectional view of the substrate of each embodiment provided by the present embodiment one. In order to achieve at least one of the advantages or other advantages, the present embodiment one discloses a substrate, the substrate has a growth surface S1, at least part of the surface of the growth surface S1 is formed with an epitaxial growth area 10. In the present embodiment, the substrate can be made of materials with low thermal conductivity, such as sapphire, silicon, silicon carbide and other materials. Of course, the material of the substrate is also considered to be a material that can match the GaN lattice, so as to be effectively applied to GaN epitaxial growth. As an example, the present embodiment preferably has a size of 4-12 inches, and the thickness of the substrate is between 0.4-2mm.

[0038] Among them, the growth surface S1 of the substrate has an epitaxial growth area 10, which refers to the area for growing epitaxial layers. Generally, the growth surface S1 of the substrate is consistent with the epitaxial growth area 10, and the epitaxial layer grows to cover the entire growth surface S1 of the substrate, for example Figure 5 Of course, the present embodiment does not exclude that the upper epitaxial growth area 10 is within the projection range of the growth surface S1 of the substrate, for example Figure 4 That is, the epitaxial layer grows to cover only part of the growth surface S1 of the substrate. It can be designed according to actual needs.

[0039] In the traditional substrate, it is generally required that the epitaxial growth area has a very flat surface to ensure the uniformity of subsequent yellow light and epitaxial wafer. However, in the conventional epitaxial process using a substrate with a flat surface, the inventors found that the epitaxial wavelength presents a typical asymmetric distribution. As Figure 1 The distribution of epitaxial wavelength on the substrate in the conventional design of the prior art is shown in the figure, wherein different color depths represent the difference of epitaxial wavelength, the green distribution area at about 10 o'clock, 2 o'clock and 6 o'clock position in the figure represents the relatively shorter epitaxial wavelength, and the red distribution area at about 12 o'clock, 4 o'clock and 8 o'clock position and the middle position represents the relatively longer epitaxial wavelength. That is, the epitaxial wavelength distribution of each region on the substrate is not uniform. As can be seen, the conventional substrate and the conventional epitaxial growth method have the problem of poor uniformity of epitaxial wavelength.

[0040] To effectively solve the above problems, the substrate is improved in the embodiment, and the uniformity of the epitaxial wavelength is compensated by adjusting the convex region 12 and the concave region 13 on the surface of the substrate. In specific implementation, please refer to Figures 6-8 , the epitaxial growth region 10 has a flat region 11, a convex region 12 and a concave region 13; the flat region 11 is a horizontal surface located on the epitaxial growth region 10; the convex region 12 is convex from the flat region 11 to the direction away from the substrate, and the concave region 13 is concave from the flat region 11 to the inside of the substrate; a plurality of convex regions 12 are located near the edge of the epitaxial growth region 10; at least one concave region 13 is closer to the center of the epitaxial growth region 10 than the convex region 12. By designing the epitaxial growth region 10 to have the convex region 12 and the concave region 13, the temperature difference of different positions on the surface of the substrate is reduced to affect the epitaxial wavelength.

[0041] , the flat region 11 refers to the horizontal region on the substrate growth surface S1, that is, neither convex away from the substrate surface nor concave to the inside of the substrate. Generally, the surface of the flat region 11 is parallel to the other side surface of the substrate opposite to the growth surface S1. The convex region 12 refers to the part on the surface of the substrate which is convex in height relative to the flat region 11 and away from the substrate. The concave region 13 refers to the part on the surface of the substrate which is concave in depth relative to the flat region 11 and to the inside of the substrate. The three regions together constitute the surface structure of the substrate. According to the actual epitaxial wavelength difference, the convex region 12 is arranged in the region with shorter wavelength, and the concave region 13 is arranged in the central region with longer wavelength, so as to balance the temperature of the surrounding convex region 12, and then compensate the epitaxial wavelength, so as to make the epitaxial wavelength of the whole substrate uniform.

[0042] In detail, please refer to Figure 2 , Figure 3 , in the epitaxial growth process, the substrate is generally placed on the pedestal, and the high-speed rotation of the pedestal and the horizontal blowing of the reaction gas flow from one side of the reaction chamber make the material uniformly deposited on the growth surface S1 of the substrate. Since the temperature of the pedestal is higher than that of the substrate, and the centrifugal force is easily generated in the high-speed rotation of the pedestal, the temperature of the substrate on the windward side where the reaction gas flow is first blown is higher, and the temperature of the leeward side where the reaction gas flow is blown later is lower. The conventional substrate and the conventional epitaxial growth method shown in Figure 2 have the problem of poor uniformity of the epitaxial wavelength. Therefore, please refer to Figure 3In the embodiment, the substrate is provided with the raised areas 12 and the recessed areas 13, and the thermal conductance of different positions is adjusted locally by the raised areas 12 and the recessed areas 13. In the epitaxial growth process, the position with the raised area 12 is arranged at a position where the epitaxial wavelength is relatively short, so as to reduce the thermal conductance of the position with the raised area 12, and then reduce the growth temperature of the position and increase the epitaxial wavelength of the position; meanwhile, the recessed area 13 is arranged at a position where the epitaxial wavelength is relatively long, so as to increase the thermal conductance of the position with the recessed area 13, and then increase the growth temperature of the position and reduce the epitaxial wavelength of the position, thereby effectively ensuring the consistency of the epitaxial wavelength of each position in the epitaxial growth area 10.

[0043] It should be noted that the raised areas 12 are arranged at intervals and can not occupy the edge of the epitaxial growth area 10 as shown in FIG. 1B, or can occupy the edge of the epitaxial growth area 10 as shown in FIG. 1C. The number and size of the raised areas 12 and the number, area, size and shape of the recessed areas 13 can be reasonably adjusted according to the actual thickness, size and shape of the substrate and the epitaxial growth conditions, and all fall within the protection scope of the present application. Figure 7 Figure 8 It should be noted that the raised areas 12 are arranged at intervals and can not occupy the edge of the epitaxial growth area 10 as shown in FIG. 1B, or can occupy the edge of the epitaxial growth area 10 as shown in FIG. 1C. The number and size of the raised areas 12 and the number, area, size and shape of the recessed areas 13 can be reasonably adjusted according to the actual thickness, size and shape of the substrate and the epitaxial growth conditions, and all fall within the protection scope of the present application.

[0044] Based on the above, in the embodiment, the raised areas 12 and the recessed areas 13 of the epitaxial growth area 10 on the substrate can effectively avoid the non-uniformity of the epitaxial wavelength in the subsequent epitaxial growth process, and improve the quality and performance of the epitaxial layer.

[0045] Further, referring to FIGS. 1B and 1C, Figure 4 Figure 5 In the embodiment, the height of the raised areas 12 and the recessed areas 13 is defined. Specifically, the thickness of the substrate at the flat area 11 is H, the height h1 from the highest point of the raised area 12 away from the substrate to the flat area 11 of the substrate is between 0.1%H and 2%H, and / or the height h2 from the lowest point of the recessed area 13 recessed into the substrate to the flat area 11 of the substrate is between 0.1%H and 2%H. Preferably, taking the thickness of the substrate as 4 inches as an example, the height h1 is between 2 microns and 8 microns, and the height h2 is between 2 microns and 8 microns. More preferably, the heights h1 and h2 are between 2 microns and 4 microns.

[0046] The above definition can avoid the problem that the height is too small to improve the difference of the epitaxial wavelength, and also avoid the problem that the height is too large to increase the difficulty of epitaxial growth and increase the dislocation density.

[0047] ​​In an optional embodiment, the projection direction perpendicular to the flat region 11 of the substrate is defined as orthographic projection, the total orthographic projection area of the plurality of raised regions 12 on the growth surface S1 is greater than the total orthographic projection area of the plurality of recessed regions 13 on the growth surface S1, and / or the total orthographic projection area of the flat region 11 on the growth surface S1 is greater than the total orthographic projection area of the plurality of recessed regions 13 on the growth surface S1.

[0048] In the actual implementation, since the area with longer epitaxial wavelength is relatively small, and the area with shorter epitaxial wavelength in the epitaxial growth region 10 is greater than the area with longer epitaxial wavelength, the uniformity of the epitaxial wavelength is ensured by setting the total orthographic projection area of the raised regions 12 to be greater than the orthographic projection area of the recessed regions 13 and the total orthographic projection area of the flat region 11 to be greater than the total orthographic projection area of the recessed regions 13.

[0049] Preferably, referring to Figure 6 , the epitaxial growth region 10 has a shortest width W, the recessed region 13 is located within a range of 0.4W from the geometric center point of the epitaxial growth region 10 in at least one horizontal direction, and the raised region 12 is located outside the range of 0.4W from the geometric center point of the epitaxial growth region 10 in at least one horizontal direction. The geometric center point of the epitaxial growth region 10 is defined as the center point of the geometric shape surrounded by the boundary of the epitaxial growth region 10. Specifically, the geometric center point refers to the point in the closed planar graph of the epitaxial growth region 10, which is located at the center of symmetry of the graph, and the distance to any point on the boundary of the epitaxial growth region 10 is equal. Generally, the epitaxial growth region 10 is circular, and the center of the circle is the geometric center point of the epitaxial growth region 10.

[0050] By limiting the positions of the recessed region 13, the raised region 12, and the geometric center point of the epitaxial growth region 10, the difference in epitaxial wavelength can be effectively improved. For example, when the width of the substrate is 4 inches, preferably, the recessed region 13 is located within a range of 35-42mm from the geometric center point of the epitaxial growth region 10 in at least one horizontal direction, and the raised region 12 is located outside the range of 35-42mm from the geometric center point of the epitaxial growth region 10 in at least one horizontal direction. Of course, the specific offset can be reasonably set according to the actual epitaxial wavelength, which is not limited here.

[0051] Further, the included angle α between the tangent line of the outer contour of the raised region 12 and the geometric center point of the epitaxial growth region 10 is between 50° and 100°, and further, the included angle β formed between the outer contours of adjacent raised regions 12 at the geometric center point of the epitaxial growth region 10 is greater than or equal to 20°. By limiting the angle of the raised region 12 as described above, the epitaxial wavelength can be effectively uniform. Of course, the specific angle can be reasonably selected according to actual needs.

[0052] In other optional embodiments, referring to Figure 7 , the plurality of raised regions 12 include a first raised region 12a, a second raised region 12b, and a third raised region 12c; wherein an included angle a1 between an outer contour of the first raised region 12a and a tangent line between the geometric center point of the epitaxial growth region 10 is between 50° and 70°; an included angle a2 between an outer contour of the second raised region 12b and a tangent line between the geometric center point of the epitaxial growth region 10 is between 50° and 70°; and an included angle a3 between an outer contour of the third raised region 12c and a tangent line between the geometric center point of the epitaxial growth region 10 is between 80° and 100°. Through the above arrangement, the epitaxial wavelength of the region on the substrate can be effectively adapted, not only the uniform epitaxial wavelength can be achieved, but also the quality of epitaxial growth can be ensured.

[0053] Referring to Figure 7 , Figure 8 , compared with the geometric center point of the epitaxial growth region 10, the geometric center point of the recessed region 13 is more inclined to the region between the first raised region 12a and the third raised region 12c, or the geometric center point of the recessed region 13 is more inclined to the region between the second raised region 12b and the third raised region 12c. Specifically, as shown in Figure 7 , Figure 8 , point A is the geometric center point of the epitaxial growth region 10, and point B is the geometric center point of the recessed region 13, and the two points do not coincide. Wherein, the geometric center point of the recessed region 13 is more inclined to which position can be set according to the actual epitaxial wavelength of the central region, which is not limited here. For example, Figure 8 , when the substrate size is 4 inches and the recessed region 13 is circular, preferably, point A is translated upward by 5-11 mm and rightward by 3-7 mm to obtain point B, and the radius of the recessed region 13 is between 15-27 mm.

[0054] On the basis of each of the above embodiments, the raised region 12 and the recessed region 13 can be formed by laser hidden cutting process. Specifically, the present embodiment controls the warping shape of the substrate wafer source by ultrafast laser internal modification technology to match the uniformity of epitaxial wavelength. Wherein, double-layer hidden cutting technology can be used to control the shape of the raised region 12 and the recessed region 13 formed by the chip wafer source, and then improve the thermal contact between the base and the substrate.

[0055] Taking the double-layer etched cut technology as an example, the first etched cut falls within the range of 0.4W to 1W. Specifically, etched cuts are made on the upper half of the substrate at the positions of the first raised region 12a, the second raised region 12b, and the third raised region 12c to bulge the substrate and form raised regions 12, reducing the thermal conductivity and temperature at these positions to compensate for the shorter wavelength. The power of the first etched cut can be selected from 0.4 to 0.6W, the pitch (etched cut line spacing) ranges from 700 to 900 μm, and the etch depth is 250 to 350 μm. After etching, the wafer surface exhibits a triangular-like raised region 12. The second etched cut falls within the range of 0 to 0.4W. Specifically, etched cuts are made on the lower half of the substrate at the position of the recessed region 13 to create a recess at this position, increasing the thermal conductivity and temperature at this position to compensate for the longer wavelength. The power of the second layer of concealed cutting is 0.95~1.15W, the pitch (spacing between concealed cutting lines) ranges from 700 to 900um, and the depth is 1150~1250um. After concealing, the overall surface shape is a triangular saddle shape with 3 raised areas 12 and 1 recessed area 13.

[0056] The principle is as follows: To compensate for the wavelength deviation, the substrate in the shorter wavelength area needs to be convex to form a raised region 12, causing the substrate to warp, reducing thermal contact and thermal conductivity. The height of the convex region substrate can be increased by 2~8μm, thereby reducing the temperature of this region by about 0.5~2℃, and the wavelength std of the entire substrate is reduced to 0.5~1μm. The substrate in the longer wavelength area is concave to form a recessed region 13, causing the substrate to warp. The height of the concave region substrate is reduced by 2~4μm, increasing thermal contact and thermal conductivity, increasing the temperature of this region by about 0.5~2℃, and further reducing the wavelength std of the substrate to below 0.5μm.

[0057] To effectively illustrate the effect of the substrate designed in this embodiment, this embodiment tests the epitaxial wavelength on the substrate having the raised region 12 and the recessed region 13, and the results are as follows: Figure 9 The diagram shows the distribution of epitaxial wavelengths on the substrate. Among them, Figure 1 and Figure 9 The only difference is the substrate surface structure; all other conditions are the same. It can be clearly seen that the epitaxial wavelength of the substrate with the raised region 12 and the recessed region 13 in this embodiment is uniformly distributed.

[0058] Therefore, by designing the raised area 12 and the recessed area 13 on the substrate surface as described above, this embodiment can effectively compensate for the asymmetrical temperature field distribution, increase the temperature of the shorter wavelength region, and compensate for the wavelength unevenness caused by the temperature field at different locations.

[0059] Example 2

[0060] The second embodiment provides a semiconductor device, which comprises the substrate as described in the first embodiment, and further comprises an epitaxial layer grown on the epitaxial growth region 10 of the growth surface S1 of the substrate, so as to effectively improve the symmetric uniformity of the light emitting wavelength. The semiconductor device can be a light emitting device with the epitaxial layer, such as a light emitting diode, a semiconductor laser, etc.

[0061] It should be noted that the substrate applied in the semiconductor device in the embodiment is used as a growth substrate for growing the epitaxial layer, and the skilled in the art can also apply the substrate mentioned in the first embodiment to any temporary growth substrate which needs to be epitaxially grown, which also falls within the protection scope of the present application.

[0062] In an optional embodiment, the standard deviation of the light emitting wavelength of the epitaxial layer on the epitaxial growth region 10 is between 0.5 and 1 nm. More preferably, the standard deviation of the light emitting wavelength of the epitaxial layer on the epitaxial growth region 10 is less than or equal to 0.5 nm. Through the above setting, the uniformity of the light emitting wavelength of the epitaxial layer can be effectively ensured, and the optical efficiency and the uniformity of the light emitting brightness of the semiconductor device can be effectively improved.

[0063] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A substrate, characterized by: The substrate has a growth surface, at least part of the surface of the growth surface forms an epitaxial growth region; the epitaxial growth region has a flat area, a raised area and a recessed area; the flat area is a horizontal surface on the epitaxial growth region; the raised area is raised away from the substrate from the flat area, and the recessed area is recessed towards the inside of the substrate from the flat area; A plurality of raised areas are located near the edge of the epitaxial growth region; at least one recessed area is closer to the center of the epitaxial growth region than the raised area.

2. The substrate of claim 1, wherein: The thickness of the substrate at the flat area position is H, and the height h1 from the highest point of the raised area away from the substrate to the flat area of the substrate is between 0.1% H and 2% H.

3. The substrate of claim 1, wherein: The thickness of the substrate at the flat area position is H, and the height h2 from the lowest point of the recessed area recessed towards the inside of the substrate to the flat area of the substrate is between 0.1% H and 2% H.

4. The substrate of claim 1, wherein: The projection direction perpendicular to the flat area of the substrate is defined as the orthographic projection, and the total area of the orthographic projection of a plurality of raised areas on the growth surface is greater than the total area of the orthographic projection of the recessed area on the surface.

5. The substrate of claim 1, wherein: The projection direction perpendicular to the flat area of the substrate is defined as the orthographic projection, and the total area of the orthographic projection of the flat area on the growth surface is greater than the total area of the orthographic projection of the recessed area on the growth surface.

6. The substrate of claim 1, wherein: The epitaxial growth region has a shortest width W, and the geometric center point of the recessed area in the epitaxial growth region is offset within a range of 0.4W in at least one horizontal direction; and the geometric center point of the raised area in the epitaxial growth region is offset outside the range of 0.4W in at least one horizontal direction.

7. The substrate of claim 1, wherein: The included angle α between the tangent line between the outer contour of the raised area and the geometric center point of the epitaxial growth region is between 50° and 100°.

8. The substrate of claim 1, wherein: The included angle β formed between the outer contours of adjacent raised areas at the geometric center point of the epitaxial growth region is greater than or equal to 20°.

9. The substrate of claim 1, wherein: A plurality of raised areas include a first raised area, a second raised area, and a third raised area; wherein the included angle α1 between the tangent line between the outer contour of the first raised area and the geometric center point of the epitaxial growth region is between 50° and 70°; the included angle α2 between the tangent line between the outer contour of the second raised area and the geometric center point of the epitaxial growth region is between 50° and 70°; and the included angle α3 between the tangent line between the outer contour of the third raised area and the geometric center point of the epitaxial growth region is between 80° and 100°.

10. The substrate of claim 9, wherein: Compared with the geometric center point of the epitaxial growth region, the geometric center point of the recessed area is more biased towards the region between the first raised area and the third raised area, or the geometric center point of the recessed area is more biased towards the region between the second raised area and the third raised area.

11. The substrate of claim 9, wherein: An included angle β1 between the outer contours of the first and second convex regions at a geometric center point of the epitaxial growth region is between 50° and 70°, an included angle β2 between the outer contours of the second and third convex regions at the geometric center point of the epitaxial growth region is between 20° and 40°, and an included angle β3 between the outer contours of the third and first convex regions at the geometric center point of the epitaxial growth region is between 50° and 70°.

12. A semiconductor device, characterized by: The substrate as claimed in any one of claims 1 to 11, further comprising an epitaxial layer on the epitaxial growth region of the substrate.

13. The semiconductor device of claim 12, wherein: A standard deviation of a light emission wavelength of the epitaxial layer on the epitaxial growth region is between 0.5 and 1 nm.

14. The semiconductor device of claim 12, wherein: A standard deviation of a light emission wavelength of the epitaxial layer on the epitaxial growth region is less than or equal to 0.5 nm.

Images