Light-emitting element and light-emitting element substrate

Abstract

The invention provides a light-emitting element which comprises an epitaxial structure and a plurality of surface microstructures. The epitaxial structure has a light emitting surface and a peripheral wall surface. The peripheral wall surface surrounds and is connected with the light-emitting surface. The plurality of surface microstructures are arranged on the light emitting surface at intervals along a plurality of directions. The plurality of directions are not perpendicular to the peripheral wall surface. The invention also provides a light-emitting element substrate comprising a plurality of light-emitting elements.

Description

Technical Field

[0001] The present invention relates to a component and a component substrate, and in particular to a light-emitting component and a light-emitting component substrate. Background Art

[0002] In addition to the advantages of low energy consumption and long material life, Micro LED Display also has excellent optical performance, such as high color saturation, fast response speed and high contrast. Therefore, in recent years, it has gradually attracted investment attention from major technology companies. In the production process of micro LEDs, due to the mismatch between the lattice constant of the epitaxial material (such as gallium nitride) and the lattice constant of the substrate used for crystal growth (such as sapphire substrate), threading dislocation defects are easily formed in the epitaxial structure layer, and the distribution positions of such defects are random.

[0003] In order to solve this problem, a method of epitaxy using a patterned-sapphire substrate (PSS) has been proposed. The PSS structure can reduce the number of the above defects by means of patterned protrusions on the substrate, and the micro-LED formed by this method will copy the pattern outline of the PSS on the surface of the side connected to the PSS. After removing the PSS, a microstructure corresponding to the PSS pattern outline will be generated on the surface of the LED. However, in the subsequent micro-LED cutting process, it is practically impossible to include the shape of the microstructure after cutting into the design basis of the exposure pattern, which results in each micro-LED cut having a random and different microstructure cutting section in response to the exposure pattern. Since the surface microstructure of the micro-LED will affect its light extraction efficiency and / or the way the light is scattered, the above-mentioned cross-sectional differences will destroy the overall light uniformity of these micro-LEDs. Summary of the invention

[0004] The present invention is directed to a light-emitting element and a light-emitting element substrate, which have better light emission uniformity.

[0005] According to an embodiment of the present invention, a light-emitting element includes an epitaxial structure and a plurality of surface microstructures. The epitaxial structure has a light-emitting surface and a peripheral wall surface. The peripheral wall surface surrounds and connects the light-emitting surface. The plurality of surface microstructures are arranged on the light-emitting surface at intervals along a plurality of directions, and the directions are not perpendicular to the peripheral wall surface.

[0006] According to an embodiment of the present invention, a light-emitting element substrate includes a carrier and a plurality of light-emitting elements. The light-emitting elements are arranged on the carrier, and each includes an epitaxial structure and a plurality of surface microstructures. The epitaxial structure has a light-emitting surface. The plurality of surface microstructures are arranged on the light-emitting surface at intervals along a plurality of directions. The orthographic projections of the plurality of epitaxial structures of the plurality of light-emitting elements on the carrier define a plurality of isolation region patterns of the carrier. The plurality of directions are not perpendicular to the extension direction of each isolation region pattern.

[0007] Based on the above, in the light-emitting element substrate of one embodiment of the present invention, the multiple arrangement directions of the multiple surface microstructures on the epitaxial structure of each light-emitting element are not perpendicular to the peripheral wall surface of the epitaxial structure. Therefore, the light uniformity of the light-emitting element and the overall light uniformity between the multiple light-emitting elements on the light-emitting element substrate can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a cross-sectional schematic diagram of a light emitting element according to an embodiment of the present invention;

[0009] Figure 2 yes Figure 1 A three-dimensional schematic diagram of an epitaxial structure;

[0010] Figure 3A and Figure 3B is a three-dimensional schematic diagram of an epitaxial structure according to some other variant embodiments of the present invention;

[0011] Figure 4A and 4B Schematic cross-sectional views of the light emitting element of the present invention at different positions;

[0012] Figure 5 It is a three-dimensional schematic diagram of a light-emitting element substrate according to an embodiment of the present invention.

[0013] Description of Reference Numerals

[0014] 1: Light-emitting element substrate;

[0015] 10: Light-emitting element;

[0016] 100, 100A, 100B: epitaxial structure;

[0017] 100es: light-emitting surface;

[0018] CS: carrier board;

[0019] CSs: surface;

[0020] DR1~DR3: first direction~third direction;

[0021] DT1~DT3: first maximum depth~third maximum depth;

[0022] E1: first electrode;

[0023] E2: second electrode;

[0024] ED1, ED2: extension direction;

[0025] EML: luminescent layer;

[0026] INS: Insulation layer;

[0027] ISOP1, ISOP2: isolation area pattern;

[0028] ND: normal direction;

[0029] OP: Opening;

[0030] PWS: Peripheral wall surface;

[0031] PWSe: edge;

[0032] SCL1: first type semiconductor layer;

[0033] SCL2: second type semiconductor layer;

[0034] SMS, SMS1, SMS2, SMS3, SMS-A, SMS-B: surface microstructure;

[0035] SWS1, SWS2: side wall surface;

[0036] θ1, θ2, θ3, α1, α2, α3: included angle. DETAILED DESCRIPTION

[0037] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0038] Figure 1 is a schematic cross-sectional view of a light emitting element according to an embodiment of the present invention. Figure 2 yes Figure 1 Schematic diagram of the epitaxial structure. Figure 3A and Figure 3B 2 is a schematic three-dimensional diagram of an epitaxial structure according to some other variant embodiments of the present invention.

[0039] Please refer to Figure 1 and Figure 2The light emitting element 10 includes an epitaxial structure 100 and a plurality of surface microstructures SMS. The epitaxial structure 100 has a light emitting surface 100es and a peripheral wall surface PWS. The peripheral wall surface PWS surrounds and connects the light emitting surface 100es. The epitaxial structure 100, for example, includes a light emitting layer EML and a first-type semiconductor layer SCL1 and a second-type semiconductor layer SCL2 disposed on opposite sides of the light emitting layer EML. The light emitting element 10 is provided with a first electrode E1 and a second electrode E2 on a side of the epitaxial structure 100 that is opposite to the light emitting surface 100es. The first electrode E1 is electrically connected to the first-type semiconductor layer SCL1. The second electrode E2 is electrically connected to the second-type semiconductor layer SCL2.

[0040] On the other hand, the light emitting element 10 may further include an insulating layer INS covering the peripheral wall surface PWS of the epitaxial structure 100 and extending between the first electrode E1 and the second semiconductor layer SCL2 and between the first electrode E1 and the light emitting layer EML, but the present invention is not limited thereto.

[0041] Furthermore, a plurality of surface microstructures SMS are arranged on the light emitting surface 100es at intervals along at least one direction. For example, in this embodiment, the surface microstructures SMS may be a plurality of micro grooves sunken from the light emitting surface 100es and each of which is conical, but not limited thereto.

[0042] In another variant embodiment, the plurality of surface microstructures SMS-A of the epitaxial structure 100A may also be a plurality of micro grooves recessed from the light-emitting surface 100es and each of which is in the shape of a pyramid, wherein the opening contour of each of the micro grooves defined by the epitaxial structure 100A is, for example, a rectangle (e.g. Figure 3A In other embodiments not shown, the pyramid vertex in each micro groove may not be limited to one. For example, the micro groove may be a polygonal pyramid, or a prism or a cylinder without a vertex. In another variant embodiment, the plurality of surface micro structures SMS-B of the epitaxial structure 100B may also be a plurality of micro grooves (such as Figure 3B As shown), the epitaxial structure 100B defines that the opening contour of each of the micro grooves is, for example, circular, and the bottom planes of the plurality of micro grooves in the shape of bosses may be non-parallel to the light emitting surface 100es.

[0043] In this embodiment, the light emitting surface 100es of the epitaxial structure 100 defines the same opening OP profile of each surface microstructure SMS, and the depth of each surface microstructure SMS along the normal direction ND of the light emitting surface 100es (ie, the distance from the cone tip to the light emitting surface 100es) is the same.

[0044] In the present embodiment, the plurality of surface microstructures SMS are arranged in a hexagonal close packing (HCP) arrangement. For example, the surface microstructures SMS may be arranged along the first direction DR1, the second direction DR2, and the third direction DR3, respectively. The angle θ1 between the first direction DR1 and the second direction DR2, the angle θ2 between the second direction DR2 and the third direction DR3, and the angle θ3 between the third direction DR3 and the first direction DR1 are all 60 degrees, but are not limited thereto.

[0045] In the present embodiment, the peripheral wall surface PWS of the epitaxial structure 100 has an edge PWSe connected to the light emitting surface 100es, and the outline of the edge PWSe is, for example, a rectangle. From another point of view, the peripheral wall surface PWS of the epitaxial structure 100 may include four sidewall surfaces, and any two adjacent sidewall surfaces of the four sidewall surfaces are perpendicular to each other. For example, the sidewall surface SWS1 and the sidewall surface SWS2 of the peripheral wall surface PWS are connected to each other and are perpendicular to each other (e.g., Figure 2 shown).

[0046] It is particularly noted that the multiple arrangement directions of the multiple surface microstructures SMS, such as the first direction DR1, the second direction DR2, and the third direction DR3, are not perpendicular to the peripheral wall surface PWS of the epitaxial structure 100. More specifically, the angle between each of these arrangement directions and any sidewall surface of the peripheral wall surface PWS may be between 5 degrees and 25 degrees, between 35 degrees and 55 degrees, or between 65 degrees and 85 degrees.

[0047] For example, the angle α1 between the first direction DR1 and the side wall surface SWS2 may be between 65 degrees and 85 degrees, and the angle α2 between the second direction DR2 and the side wall surface SWS1 may be between 65 degrees and 85 degrees, preferably 75 degrees. The angle α3 between the third direction DR3 and the side wall surface SWS1 or the side wall surface SWS2 may be between 35 degrees and 55 degrees, preferably 45 degrees. In other words, the angle between the first direction DR1 and the side wall surface SWS1 may be between 5 degrees and 25 degrees, and the angle between the second direction DR2 and the side wall surface SWS2 may be between 5 degrees and 25 degrees, preferably 15 degrees.

[0048] By means of the above-mentioned angle configuration relationship between the arrangement direction and the side wall surface, it can be ensured that the cut shapes of the plurality of surface microstructures SMS on the cut sections (i.e., the side wall surface) of the epitaxial structure 100 present irregularities in size or depth. It is particularly noted that the preferred angle design corresponding to different angle ranges here corresponds to the middle value of the angle range (e.g., 15 degrees, 45 degrees, or 75 degrees). In detail, under the aforementioned hexagonal closest packing arrangement, the angle relationship between the arrangement direction and the side wall surface presents a regularity of one cycle every 30 degrees. Therefore, for the cut sections of the epitaxial structure 100, within the cycle in which the angle between every two cut sections and the surface microstructure SMS is 0 degrees, selecting a range near the middle value (i.e., 15 degrees, 45 degrees, or 75 degrees) can ensure that the contours of all epitaxial structures 100 on all cut sections present irregularities and have surface microstructures SMS with similar light emitting effects, and this irregularity will not be destroyed due to the precision error of the cutting process.

[0049] For example, from Figure 1 A cross-sectional view or Figure 2 It can be seen from the side wall SWS1 that four surface microstructures of different sizes and depths can be revealed on a cut section (i.e., one side wall) of the epitaxial structure 100. Among them, the first surface microstructure SMS1, the second surface microstructure SMS2, and the third surface microstructure SMS3 have a first maximum depth DT1, a second maximum depth DT2, and a third maximum depth DT3 along the normal direction ND of the light emitting surface 100es, respectively, and the first maximum depth DT1, the second maximum depth DT2, and the third maximum depth DT3 are different from each other.

[0050] More specifically, among the plurality of surface microstructures SMS revealed by any cutting section of the epitaxial structure 100 , at least three surface microstructures SMS have different maximum depths on the cutting section.

[0051] First, if the epitaxial structure is cut in a cross section parallel to or perpendicular to the arrangement direction of the plurality of surface microstructures SMS, then the maximum depth of the surface microstructure SMS revealed by any cut section of the epitaxial structure is at most two. For example, if the epitaxial structure is cut along the first direction DR1, the cut section will present two states. One is to reveal a surface microstructure SMS having only a single maximum depth (for example, when cutting at Figure 2 The other is that the cutting section is located near the tangent line of the surface microstructures SMS of two adjacent columns. At this time, the surface microstructures SMS from both sides of the cutting section will be exposed at the same time, and the maximum depths of the surface microstructures SMS on both sides may be different, but the depths are extremely small. Figure 4A as well as Figure 4BThey are respectively a cross-sectional schematic diagram of a cutting section located on line DR1, and a cross-sectional schematic diagram of a cutting section located near a tangent line of the surface microstructure SMS of two adjacent columns. Figure 4A as well as Figure 4B It can be seen that the position of the cutting section will significantly change the shape of the exposed surface microstructure SMS. Figure 4A In , the exposed surface microstructure SMS has the largest area and is densely distributed; Figure 4B In the example, since the cutting section is located at the tangent line of the surface microstructure SMS of two adjacent rows, the area of ​​the surface microstructure SMS exposed is almost zero. Figure 4B The incident angle of the light emitted from the middle light emitting layer EML to the cut section is enlarged, so that the proportion of light that undergoes total reflection (towards the light emitting surface) becomes higher, so it is relatively Figure 4A The light pattern of the epitaxial structure 100 is more concentrated.

[0052] That is to say, if the epitaxial structure is cut parallel to or perpendicular to the arrangement direction of the multiple surface microstructures SMS, the multiple epitaxial structures cut out will have obvious differences in light output brightness, which will affect the light output uniformity between different light-emitting elements. As the size of light-emitting elements gradually decreases, the brightness difference caused by the uneven surface microstructure of the cut section will become more obvious. In addition, as the exposure pattern of the lithography process becomes more dense, the frequency of the above phenomenon on the semiconductor wafer will also increase.

[0053] refer to Figure 2 Since the cut section of the epitaxial structure 100 of the present embodiment is neither parallel nor perpendicular to the arrangement direction of the plurality of surface microstructures SMS, the plurality of surface microstructures SMS exposed on any cut section of the epitaxial structure 100 can have at least three maximum depths. More specifically, the depth diversity of the surface microstructures SMS exposed on the cut section of the epitaxial structure 100 of the present embodiment is better, and such a structure uniformly appears on all cut sections of each epitaxial structure 100, so the difference in light output brightness between the cut plurality of epitaxial structures 100 can be significantly reduced.

[0054] It should be noted that in the drawings, the number of surface microstructures SMS on the light-emitting surface 100es of the epitaxial structure 100 is only for exemplary purposes and does not limit the present invention. In other embodiments, the number of surface microstructures SMS of the epitaxial structure can be adjusted according to different product requirements or designs.

[0055] In addition, the specific angles exemplified in the above embodiments are not intended to be certain limitations on the meaning of the term "non-perpendicular" in the present invention. In detail, since the size of the surface microstructures SMS is generally very small, the sidewall surface of each epitaxial structure 100B may correspond to many surface microstructures SMS. In this state, only a small angle deviation, such as 87 to 89 degrees (i.e., a deviation of 1 to 3 degrees), is required to allow these surface microstructures SMS to present a variety of depths, and each sidewall surface uniformly exhibits this feature.

[0056] Figure 5 FIG. 1 is a perspective view of a light emitting element substrate according to an embodiment of the present invention. First, for the sake of clarity, Figure 5 The light emitting element 10 in FIG. 1 only shows its epitaxial structure 100 .

[0057] Please refer to Figure 5 The light emitting element substrate 1 includes a carrier board CS and a plurality of light emitting elements 10 disposed on the carrier board CS. Figure 1 For the light emitting element 10, the detailed structural features and configuration relationship thereof can be found in the relevant paragraphs of the aforementioned embodiment, which will not be described in detail here.

[0058] In the present embodiment, the orthographic projections of the plurality of epitaxial structures 100 of the plurality of light emitting elements 10 on the surface CSs of the carrier CS define the plurality of isolation region patterns of the carrier CS. More specifically, the peripheral wall surfaces PWS of the respective epitaxial structures 100 define the isolation region patterns, such as the plurality of first isolation region patterns ISOP1 and the plurality of second isolation region patterns ISOP2. For example, the arrangement direction of the plurality of first isolation region patterns ISOP1 is perpendicular to the arrangement direction of the plurality of second isolation region patterns ISOP2, and the extension direction ED1 of the first isolation region patterns ISOP1 is perpendicular to the extension direction ED2 of the second isolation region patterns ISOP2.

[0059] It is particularly noted that the arrangement directions of the plurality of surface microstructures SMS on the epitaxial structure 100 of each light emitting element 10, such as the first direction DR1, the second direction DR2 and the third direction DR3, are not perpendicular to any isolation region pattern. For example, in the present embodiment, the plurality of epitaxial structures 100 on the carrier CS are obtained by etching an epitaxial structure layer formed by the same epitaxial process, wherein the etching step is, for example, a photolithography etching technique, and the arrangement directions of the mask patterns used (such as a plurality of light shielding patterns or a plurality of light transmitting patterns respectively defining the plurality of epitaxial structures 100) are not parallel to or perpendicular to all arrangement directions of the plurality of surface microstructures SMS on the epitaxial structure 100.

[0060] By means of such a design, the maximum depth diversity of the surface microstructure SMS exposed on any cut section of each of the multiple epitaxial structures 100 produced after etching can be improved. That is, the configuration distribution of each epitaxial structure 100 on the cut section is more random and scattered. Therefore, the difference in light output brightness between the multiple light-emitting elements 10 formed by these epitaxial structures 100 can be significantly reduced.

[0061] In this embodiment, since the isolation region pattern is defined by the peripheral wall surface PWS of the epitaxial structure 100 of the light emitting element 10, the extension direction of the isolation region pattern is parallel to one side wall surface of the peripheral wall surface PWS. In other words, the angle between the arrangement direction of the surface microstructure SMS and the extension direction of the isolation region pattern is the angle between the arrangement direction of the surface microstructure SMS and the corresponding side wall surface.

[0062] For example, the angle between the first direction DR1 and the extension direction ED1 of the first isolation region pattern ISOP1 (i.e., the angle α1 between the first direction DR1 and the sidewall surface SWS2 defining the first isolation region pattern ISOP1) is between 65 degrees and 85 degrees. The angle between the second direction DR2 and the extension direction ED2 of the second isolation region pattern ISOP2 (i.e., the angle α2 between the second direction DR2 and the sidewall surface SWS1 defining the second isolation region pattern ISOP2) is between 65 degrees and 85 degrees, preferably, for example, 75 degrees. The angle between the third direction DR3 and the extension direction ED2 of the second isolation region pattern ISOP2 (i.e., the angle α3 between the third direction DR3 and the sidewall surface SWS1 defining the second isolation region pattern ISOP2) is between 35 degrees and 55 degrees, preferably, for example, 45 degrees.

[0063] In other words, the angle between the first direction DR1 and the extension direction ED2 of the second isolation region pattern ISOP2 may be between 5 and 25 degrees, and the angle between the second direction DR2 and the extension direction ED1 of the first isolation region pattern ISOP1 may be between 5 and 25 degrees, preferably 15 degrees. The angle between the third direction DR3 and the extension direction ED1 of the first isolation region pattern ISOP1 may be between 35 and 55 degrees, preferably 45 degrees.

[0064] By means of the above-mentioned arrangement direction and the angle configuration relationship between the isolation region pattern, it can be ensured that the cut shapes of the multiple surface microstructures SMS on each epitaxial structure 100 on the cut section (i.e., the side wall surface) of the epitaxial structure 100 show irregularities in size or depth. It is particularly noted that the preferred angle design corresponding to different angle ranges, i.e., the middle value of the corresponding angle range (e.g., 15 degrees, 45 degrees, or 75 degrees), can ensure that the contours of all epitaxial structures 100 on all cut sections show irregularities, and this irregularity will not be destroyed due to the precision error of the cutting process. Accordingly, the overall light uniformity of the multiple light-emitting elements 10 on the carrier CS can be significantly improved.

[0065] In the above description, the present embodiment can realize the angle between the peripheral wall surface PWS of the epitaxial structure 100 and each extension direction by rotating the isolation region pattern, but the present invention is not limited thereto. For example, in addition to rotating the isolation region pattern, the isolation region pattern can also be translated to obtain a more uniform surface microstructure SMS.

[0066] From another perspective, since the multiple epitaxial structures 100 of the present embodiment are obtained by etching the epitaxial structure layer formed by the same process, the multiple surface microstructures SMS of two adjacent epitaxial structures 100 separated by any isolation region pattern can be arranged in multiple rows along at least one arrangement direction. For example, two epitaxial structures 100 (e.g., Figure 5 The plurality of surface microstructures SMS on the two epitaxial structures 100 (for example, the two epitaxial structures 100 at the upper right corner and the lower right corner or the upper left corner and the lower left corner) can be arranged in a plurality of rows along the first direction DR1 or the third direction DR3. Figure 5 The plurality of surface microstructures SMS on the two epitaxial structures 100 at the upper left corner and the upper right corner or the lower left corner and the lower right corner may be arranged in a plurality of colinear rows along the second direction DR2 or the third direction DR3.

[0067] That is, even if two adjacent epitaxial structures 100 are separated by the isolation region pattern, a portion of the surface microstructure SMS on one epitaxial structure 100 and a portion of the surface microstructure SMS on the other epitaxial structure 100 can still be collinearly arranged along a virtual straight line crossing the isolation region pattern.

[0068] In summary, in the light-emitting element substrate of one embodiment of the present invention, the multiple arrangement directions of the multiple surface microstructures on the epitaxial structure of each light-emitting element are not perpendicular to the peripheral wall surface of the epitaxial structure. Therefore, the light uniformity of the light-emitting element and the overall light uniformity between the multiple light-emitting elements on the light-emitting element substrate can be effectively improved.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light emitting element, characterized in that: include: An epitaxial structure having a light emitting surface and a peripheral wall surface, wherein the peripheral wall surface surrounds and connects the light emitting surface; as well as A plurality of surface microstructures are arranged on the light emitting surface at intervals along a plurality of directions, and each of the plurality of directions is not perpendicular to the peripheral wall surface.

2. The light emitting element according to claim 1, characterized in that One side wall surface of the peripheral wall surface reveals the first surface microstructure, the second surface microstructure and the third surface microstructure of the multiple surface microstructures, and the first surface microstructure, the second surface microstructure and the third surface microstructure have a first maximum depth, a second maximum depth and a third maximum depth respectively along the normal direction of the light-emitting surface, and the first maximum depth, the second maximum depth and the third maximum depth are different from each other.

3. The light emitting element according to claim 1, wherein: The edge contour of the peripheral wall surface connecting the light emitting surface is rectangular.

4. The light emitting element according to claim 1, wherein: The plurality of surface microstructures are arranged on the light emitting surface in a hexagonal closest packing manner.

5. The light emitting element according to claim 4, characterized in that The plurality of surface microstructures are arranged along a first direction and a second direction respectively, and an angle between the first direction and the second direction is 60 degrees.

6. The light emitting element according to claim 1, wherein: The light emitting surface defines that the opening profiles of each of the plurality of surface microstructures are the same.

7. The light emitting element according to claim 6, characterized in that The maximum depth of each of the plurality of surface microstructures along the normal direction of the light emitting surface is the same.

8. The light emitting element according to claim 1, characterized in that The multiple surface microstructures are arranged along a first direction, the peripheral wall surface has multiple sidewall surfaces, and the angle between the first direction and any one of the multiple sidewall surfaces is between 5 degrees and 25 degrees, between 35 degrees and 55 degrees, or between 65 degrees and 85 degrees.

9. A light emitting element substrate, characterized in that: include: Carrier board; as well as A plurality of light-emitting elements are arranged on the carrier, each of the plurality of light-emitting elements comprising: Epitaxial structure, with a light emitting surface; as well as A plurality of surface microstructures are arranged at intervals along a plurality of directions on the light-emitting surface, wherein the orthographic projections of the plurality of epitaxial structures of the plurality of light-emitting elements on the carrier define a plurality of isolation region patterns of the carrier, and each of the plurality of directions is not perpendicular to an extension direction of each of the plurality of isolation region patterns.

10. The light emitting element substrate according to claim 9, characterized in that: The plurality of epitaxial structures further have a plurality of peripheral wall surfaces defining the plurality of isolation region patterns, and the edge contour of each of the plurality of peripheral wall surfaces connected to the light emitting surface is a rectangle.

11. The light emitting element substrate according to claim 9, characterized in that: The plurality of epitaxial structures include a first one and a second one separated by one of the plurality of isolation region patterns and adjacent to each other, wherein the plurality of surface microstructures of the first one and the plurality of surface microstructures of the second one are arranged in a plurality of rows and in a collinear manner along one of the plurality of directions.

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