CN110444639B - Light-emitting element and light-emitting element structure - Google Patents

Abstract

The present invention provides a light-emitting element including an epitaxial structure, a first electrode and a second electrode. The epitaxial structure has a plurality of first defect density regions, a plurality of second defect density regions and a first surface and a second surface opposite to each other. The plurality of first defect density regions and the plurality of second defect density regions are alternately arranged between the first surface and the second surface. The defect density of each first defect density region is lower than the defect density of each second defect density region, and the number of the plurality of first defect density regions is at least ten. The epitaxial structure also includes a light-emitting layer, a first-type semiconductor layer and a second-type semiconductor layer arranged on opposite sides of the light-emitting layer. The first electrode and the second electrode are electrically connected to the first-type semiconductor layer and the second-type semiconductor layer, respectively. A light-emitting element structure using a light-emitting element is also proposed.

Description

Light-emitting element and light-emitting element structure

technical field

The present invention relates to a light-emitting element and a light-emitting element structure, in particular to a light-emitting element with an epitaxial structure and a light-emitting element structure.

Background technique

In recent years, under the circumstance that the manufacturing cost of organic light-emitting diode (OLED) display panel is too high and its service life cannot compete with the current mainstream displays, Micro LED Display (Micro LED Display) has gradually attracted attention. Investment vision of major technology companies. In addition to the advantages of low power consumption and long material life, micro LED displays also have excellent optical performance, such as high color saturation, fast response speed and high contrast.

However, in the fabrication process of micro light-emitting diodes, since the lattice constant of the epitaxial material (eg, gallium nitride) does not match the lattice constant of the substrate for crystal growth (eg, the sapphire substrate), the epitaxial structure layer is prone to Threading dislocation defects are formed, and the distribution positions of such defects are random. Therefore, when this type of epitaxial structure layer is applied to a plurality of micro-light-emitting elements, the uneven distribution of dislocation defects may easily cause the respective emission wavelengths of these micro-light-emitting elements to be different, resulting in uneven color rendering of the micro-light-emitting element display device.

SUMMARY OF THE INVENTION

The present invention provides a light-emitting element structure with better uniformity of color rendering.

The present invention provides a light-emitting element with good light-emitting uniformity.

The present invention provides a light-emitting element whose epitaxial structure has a relatively regular and uniform distribution of dislocation defects.

The light-emitting element structure of the present invention includes a patterned substrate, an epitaxial structure, a first electrode and a second electrode. The patterned substrate includes a base material and a plurality of three-dimensional patterns. These three-dimensional patterns are integrally formed with the substrate, and these three-dimensional patterns are separately arranged on the substrate. The epitaxial structure is disposed on the patterned substrate and has a plurality of first defect density regions and a plurality of second defect density regions. The first defect density regions correspond to the three-dimensional patterns, respectively. The defect density of each of the first defect density regions is lower than that of each of the second defect density regions, and the number of these first defect density regions is at least ten. The epitaxial structure further includes a light-emitting layer, a first-type semiconductor layer and a second-type semiconductor layer disposed on opposite sides of the light-emitting layer. The first electrode and the second electrode are respectively electrically connected to the first type semiconductor layer and the second type semiconductor layer.

In an embodiment of the present invention, the ratio of the defect density of any second defect density region to the defect density of any first defect density region of the light-emitting element structure is greater than or equal to 10.

In an embodiment of the present invention, each of the three-dimensional patterns of the light-emitting element structure has a base width and a height, and the ratio of the height to the base width is between 0.2 and 0.9.

In an embodiment of the present invention, there is an interval between any two adjacent three-dimensional patterns in the above-mentioned light-emitting element structure, and the interval is less than or equal to 0.5 μm.

In an embodiment of the present invention, the light-emitting layer of the above-mentioned light-emitting element structure includes a plurality of first parts and a plurality of second parts. The plurality of first portions are located in the plurality of first defect density regions, and the plurality of second portions are located in the plurality of second defect density regions. The plurality of first portions have a first thickness, the plurality of second portions have a second thickness, and the first thickness is greater than the second thickness.

In an embodiment of the present invention, each three-dimensional pattern of the above-mentioned light-emitting element structure is a convex structure.

In an embodiment of the present invention, each of the plurality of first portions of the light-emitting element structure has a first doping metal concentration, and each of the plurality of second portions has a second doping metal concentration, and the first doping metal concentration is high at the second doping metal concentration.

In an embodiment of the present invention, the number of the plurality of first defect density regions arranged in one direction in the epitaxial structure of the light-emitting element structure is at least ten.

In an embodiment of the present invention, at least part of the first defect density regions and at least part of the second defect density regions of the light-emitting element structure are alternately arranged on the patterned substrate along the direction.

In an embodiment of the present invention, the number of helical dislocation defects in the first defect density region of the above-mentioned light-emitting element structure is one or more, and the number of helical dislocation defects in the second defect density region is two or more.

In an embodiment of the present invention, there is a distance between any two adjacent three-dimensional patterns in the above-mentioned light-emitting element structure, and the distance is greater than 500 nanometers and less than or equal to 2500 nanometers.

The light-emitting element of the present invention includes an epitaxial structure, a plurality of three-dimensional patterns, a first electrode and a second electrode. The epitaxial structure has a first surface and a second surface opposite to each other and a plurality of first defect density regions and a plurality of second defect density regions. A plurality of three-dimensional patterns and the epitaxial structure are integrally formed and arranged on the first surface separately from each other. The first defect density regions correspond to the three-dimensional patterns, respectively. The defect density of each of the first defect density regions is lower than that of each of the second defect density regions, and the number of these first defect density regions is at least ten. The epitaxial structure further includes a light-emitting layer, a first-type semiconductor layer and a second-type semiconductor layer disposed on opposite sides of the light-emitting layer. The first electrode and the second electrode are respectively electrically connected to the first type semiconductor layer and the second type semiconductor layer.

In an embodiment of the present invention, the first electrode and the second electrode of the light-emitting element are electrically connected to the epitaxial structure through the first surface and the second surface respectively, and the upper surface of the first electrode is conformal to the epitaxial structure the first surface.

In an embodiment of the present invention, the above-mentioned roughness of the first surface of the epitaxial structure of the light-emitting element is greater than the roughness of the second surface of the epitaxial structure.

In an embodiment of the present invention, each three-dimensional pattern of the above-mentioned light-emitting element is a concave structure.

The light-emitting element of the present invention includes an epitaxial structure, a first electrode and a second electrode. The epitaxial structure has a first surface and a second surface opposite to each other, a plurality of first defect density regions and a plurality of second defect density regions. The first defect density regions and the second defect density regions are alternately arranged in a direction between the first surface and the second surface. The defect density of each of the first defect density regions is lower than that of each of the second defect density regions, and the number of these first defect density regions is at least ten. The epitaxial structure further includes a light-emitting layer, a first-type semiconductor layer and a second-type semiconductor layer disposed on opposite sides of the light-emitting layer. The first electrode and the second electrode are respectively electrically connected to the first type semiconductor layer and the second type semiconductor layer.

Based on the above, in the light-emitting element and the light-emitting element structure according to an embodiment of the present invention, the epitaxial structure has a plurality of alternately arranged first defect density regions and second defect density regions, and the defect density of the first defect density region is lower than The defect density of the second defect density region. With the number of the first defect density regions being at least ten, the dislocation defects of the epitaxial structure can be distributed more regularly and uniformly, thereby improving the light emitting uniformity of the light emitting element and the color rendering uniformity of the light emitting element structure.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

Description of drawings

1 is a schematic cross-sectional view of a light-emitting element structure according to an embodiment of the present invention;

FIG. 2 is an enlarged schematic view of a partial region of the light-emitting element structure of FIG. 1;

3 is a schematic cross-sectional view of the light-emitting element of FIG. 1;

4A is a schematic perspective view of a partial area of a patterned substrate according to another embodiment of the present invention;

4B is a schematic perspective view of a partial area of a patterned substrate according to another embodiment of the present invention;

5 is a schematic cross-sectional view of a light-emitting element according to another embodiment of the present invention;

6 is a schematic cross-sectional view of a light-emitting element according to another embodiment of the present invention;

7 is a schematic cross-sectional view of a light-emitting element according to still another embodiment of the present invention.

Description of reference numbers:

1: Light-emitting element structure

10, 10A, 11, 12: Light-emitting elements

50, 50A, 50B: Patterned substrates

50s, 151As, 151Bs: upper surface

51: Substrate

52, 52A, 52B, 111: Three-dimensional pattern

100, 100A, 100B: epitaxial structure

100s1, 100s1R: first surface

100s2: Second Surface

110, 110A: first type semiconductor layer

120: Light Emitting Layer

120a: Part One

120b: Part II

121: Energy Well Layer

122: Energy barrier layer

130: second type semiconductor layer

151, 151A, 151B: first electrodes

152: Second electrode

160: Insulation layer

DM: Doped Metal

DR1: first defect density region

DR2: Second defect density region

H: height

P: Pitch

S: interval

TD: Spiral Displacement Defect

T1: first thickness

T2: Second thickness

W: Bottom width

X, X1, X2, X3, Z: direction

Detailed ways

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

FIG. 1 is a schematic cross-sectional view of a light-emitting element structure according to an embodiment of the present invention. FIG. 2 is an enlarged schematic view of a partial region of the light-emitting element structure of FIG. 1 . FIG. 3 is a schematic cross-sectional view of the light-emitting element of FIG. 1 . It is particularly noted that, for the sake of clarity, FIG. 1 omits the illustration of the energy well layer 121 , the energy barrier layer 122 and the doped metal DM in FIG. 2 . Referring to FIG. 1 , the light emitting device structure 1 includes a patterned substrate 50 and an epitaxial structure 100 . The epitaxial structure 100 is disposed on the patterned substrate 50 . In detail, the patterned substrate 50 includes a base material 51 and a plurality of three-dimensional patterns 52 , and the plurality of three-dimensional patterns 52 are arranged on the base material 51 along the direction X. As shown in FIG. In this embodiment, the substrate 51 is a substrate suitable for epitaxial growth, such as a sapphire substrate, a silicon wafer (silicon wafer) substrate, a silicon carbide (silicon carbide) substrate or a polymer substrate, but the present invention Not limited to this.

Further, the plurality of three-dimensional patterns 52 are integrally formed with the base material 51 . That is, the three-dimensional pattern 52 and the base material 51 are made of the same material and are seamlessly connected. For example, the three-dimensional pattern 52 is an arc-shaped convex structure protruding from the substrate 51, so that in the subsequent epitaxy process, a plurality of first defect density regions DR1 corresponding to the convex structure are easily generated, but the present invention does not use This is limited. In this embodiment, the three-dimensional pattern 52 has a bottom width W and a height H in the direction X and the direction Z, respectively, and the bottom width W of the three-dimensional pattern 52 can be selectively larger than the height H of the three-dimensional pattern 52, but the present invention does not use This is limited. According to other embodiments, the bottom width W of the three-dimensional pattern 52 may also be smaller than the height H of the three-dimensional pattern 52 .

In a preferred embodiment, the bottom width W of the three-dimensional pattern 52 can be between 0.1 μm and 2.5 μm, and the height H can be between 10 nanometers and 1500 nanometers, which helps to improve the height of the epitaxial structure 100 . Light extraction efficiency. In another preferred embodiment, the ratio of the height H to the bottom width W of the three-dimensional pattern 52 may be between 0.2 and 0.9. When the ratio of the height H to the bottom width W is greater than 0.9, excessive defects will occur in the epitaxial structure formed on the patterned substrate 50 subsequently, resulting in a decrease in the light extraction efficiency. On the contrary, when the ratio of the height H to the bottom width W is less than 0.2, the light extraction efficiency of the epitaxial structure formed on the patterned substrate 50 subsequently cannot be improved.

On the other hand, any two adjacent three-dimensional patterns 52 have an interval S and a pitch P, and the interval S can be less than or equal to 0.5 microns, and the distance P can be greater than or equal to 500 nanometers and less than or equal to 2500 nanometers. The epitaxial structure 100 on the chemical substrate 50 has better light extraction efficiency. In this embodiment, the interval S between any two adjacent three-dimensional patterns 52 can be selectively smaller than the bottom width W of the three-dimensional patterns 52 . However, the present invention is not limited thereto, and according to other embodiments, the interval S between any two adjacent three-dimensional patterns 52 may also be greater than the bottom width W of the three-dimensional patterns 52 . It is particularly noted that, in this embodiment, the number of three-dimensional patterns 52 is exemplified by taking ten as an example, which does not mean that the present invention is limited by this. According to other embodiments, the number of three-dimensional patterns 52 may also be Eleven or more.

Further, the epitaxial structure 100 has a first surface 100s1 and a second surface 100s2 opposite to each other, and the epitaxial structure 100 is connected to the patterned substrate 50 through the first surface 100s1. In other words, the first surface 100s1 of the epitaxial structure 100 can be conformal to the upper surface 50s of the patterned substrate 50, but the invention is not limited thereto. The epitaxial structure 100 also has a plurality of first defect density regions DR1 and a plurality of second defect density regions DR2, and these first defect density regions DR1 correspond to the above-mentioned plurality of three-dimensional patterns 52 . More specifically, the first defect density regions DR1 are respectively overlapped with the above-mentioned plurality of three-dimensional patterns 52 in the normal direction of the substrate 51 (ie, the direction Z), and any two adjacent first defect density regions DR1 are overlapped with each other. A second defect density region DR2 is disposed therebetween. From another point of view, the above-mentioned three-dimensional patterns 52 can roughly define a plurality of first defect density regions DR1, a plurality of first defect density regions DR1 and a plurality of second defect density regions DR2 of the epitaxial structure 100 They are alternately arranged on the patterned substrate 50 along the direction X (as shown in FIG. 2 ).

On the other hand, the dislocation density of the first defect density region DR1 is lower than that of the second defect density region DR2. For example, in this embodiment, the volume of the space occupied by the first defect density region DR1 is larger than the volume of the space occupied by the second defect density region DR2, and the threading dislocation defect located in the first defect density region DR1 )TD is less than the number of helical dislocation defects TD located in the second defect density region DR2. However, the present invention is not limited thereto, and according to other embodiments, the volume of the space occupied by the first defect density region DR1 may also be smaller than the volume of the space occupied by the second defect density region DR2 or the helical dislocation located in the first defect density region DR1 The number of defects TD is greater than the number of helical dislocation defects TD located in the second defect density region DR2, as long as the defect density of the first defect density region DR1 is lower than that of the second defect density region DR2. In a preferred embodiment, the ratio of the defect density of any second defect density region DR2 to the defect density of any first defect density region DR1 may be greater than or equal to 10, thereby uniformly dispersing the stress in the epitaxial layer , to improve the epitaxial quality of the subsequent process and improve the uniformity of light emission.

For example, in one embodiment, the defect density of the first defect density region DR1 of the GaN epitaxial structure formed on the patterned substrate 50 using sapphire as the base material 51 is 10 ⁷ (cm ⁻² ) to 10 ⁸ (cm ⁻² ), and the defect density of the second defect density region DR2 is greater than or equal to 10 ⁹ (cm ⁻² ). It is particularly noted that the defect density of the first defect density region DR1 here may also be the average value of defect densities of a plurality of first defect density regions DR1, and the defect density of the second defect density region DR2 may also be a plurality of first defect density regions DR2. The average defect density of the two defect density regions DR2 is not limited in the present invention.

It should be noted that the helical dislocation defect TD shown in this embodiment extends from the first surface 100s1 to the second surface 100s2 of the epitaxial structure 100 , but the invention is not limited thereto. In other embodiments, some of the helical dislocation defects TD only penetrate through the light emitting layer 120 and do not extend to the second surface 100 s 2 of the epitaxial structure 100 . On the other hand, in this embodiment, the number of the helical dislocation defects TD located in the second defect density region DR2 is exemplified by one example, which does not mean that the present invention is limited thereto. In other embodiments, the number of helical dislocation defects TD located in the first defect density region DR1 and the second defect density region DR2 may also be one or more and two or more respectively, as long as the helical dislocation defects located in the first defect density region DR1 The defect TD density may be less than the TD density of the helical dislocation defects located in the second defect density region DR2.

It is particularly noted that, in this embodiment, the number of the first defect density regions DR1 arranged in the direction X of the epitaxial structure 100 is exemplified by taking ten as an example, but it does not mean that the present invention is limited by this. . According to other embodiments, the number of the plurality of first defect density regions DR1 arranged in the direction X of the epitaxial structure may also be more than eleven. More specifically, in the epitaxial structure 100 of the present invention, the plurality of first defect density regions DR1 (or the The number of the three-dimensional patterns 52) of the patterned substrate 50 is at least ten. Accordingly, the dislocation of the epitaxial structure 100 can be distributed more regularly and uniformly. On the contrary, if the number of the first defect density regions DR1 (or the three-dimensional patterns 52 of the patterned substrate 50 ) is less than ten, the dislocation defects of the epitaxial structure 100 are likely to gather in a specific area, resulting in the epitaxial structure 100 The light uniformity is poor.

Further, the epitaxial structure 100 includes a first-type semiconductor layer 110 , a light-emitting layer 120 and a second-type semiconductor layer 130 , wherein the light-emitting layer 120 is sandwiched between the first-type semiconductor layer 110 and the second-type semiconductor layer 130 , And the first type semiconductor layer 110 and the second type semiconductor layer 130 respectively have a first surface 100s1 and a second surface 100s2. On the other hand, the light-emitting element structure 1 further includes a first electrode 151 and a second electrode 152 , and the first electrode 151 and the second electrode 152 are electrically connected to the first-type semiconductor layer 110 and the second-type semiconductor layer 130 , respectively. It is particularly noted that the epitaxial structure 100, the first electrode 151 and the second electrode 152 here can constitute a light-emitting element 10 (as shown in FIG. 3 ). It should be understood that, in other embodiments, a plurality of light-emitting elements 10 can also be formed on the patterned substrate at the same time, as long as the number of the first defect density regions DR1 of each light-emitting element 10 is at least ten. The light emitting uniformity of each light-emitting element 10 is improved.

In this embodiment, the first electrode 151 and the second electrode 152 are disposed on the same side of the epitaxial structure 100 . More specifically, the light-emitting element 10 is, for example, a lateral type Micro Light-Emitting Diode (Micro LED) element, but the invention is not limited thereto. In other embodiments, the light-emitting element may also be a flip-chip type micro light-emitting diode. As used herein, "mini" light emitting diodes are meant to have dimensions ranging from 1 μm to 100 μm. In some embodiments, the microdiodes may have a maximum width of one of 20 μm, 10 μm, or 5 μm. In some embodiments, the miniature diodes may have a maximum height of less than one of 20 μm, 10 μm, or 5 μm. It should be understood, however, that embodiments of the present invention are not necessarily so limited, as certain embodiments are applicable to larger and perhaps smaller scales.

Referring to FIG. 2 , in this embodiment, the light emitting layer 120 includes a plurality of well layers 121 and a plurality of barrier layers 122 stacked alternately, wherein the energy gap of the energy barrier layers 122 is greater than the energy The energy gap of the well layer 121 . That is, the light emitting layer 120 of the present embodiment has a multiple quantum well structure. In this embodiment, the material of the energy barrier layer 122 is, for example, gallium nitride (GaN), and the material of the energy well layer 121 is, for example, indium gallium nitride (InGaN). That is to say, the main difference between the energy well layer 121 and the energy barrier layer 122 in this embodiment is that the energy well layer 121 includes an additional doped metal DM (eg, indium atoms), and the mole percentage of gallium atoms thereof is different from that of the energy barrier layer. The mole percent of gallium atoms of layer 122. However, the present invention is not limited thereto, and according to other embodiments, the energy well layer 121 and the energy barrier layer 122 may also be aluminum gallium indium phosphide (AlGaInP) or other suitable materials. It should be noted that the number of the energy well layers 121 and the energy barrier layers 122 in this embodiment is exemplified by taking two as an example, which does not mean that the present invention is limited thereto. In other embodiments, the number of the energy well layers 121 and the energy barrier layers 122 may be three or more.

Since the defect density of the first defect density region DR1 is smaller than that of the second defect density region DR2, the first thickness T1 of the first portion 120a of the light emitting layer 120 (eg, the multiple quantum well structure) located in the first defect density region DR1 is greater than the light emitting layer The layer 120 is located at the second thickness T2 of the second portion 120b of the second defect density region DR2. Therefore, the doped metal DM (eg, indium atoms) tends to be distributed in the first defect density region DR1 of the light emitting layer 120 (ie, the first portion 120 a ) having a larger thickness. For example, the first thickness T1 here can be the average thickness of the first portions 120a of the light-emitting layer 120 located in the first defect density regions DR1, and the second thickness T2 can be the thickness of the light-emitting layer 120 located in the first defect density regions DR1. The average value of the thicknesses of the plurality of second portions 120b of the two defect density regions DR2.

From another point of view, the plurality of first portions 120a of the light emitting layer 120 located in the plurality of first defect density regions DR1 each have a first doping metal concentration, and the light emitting layer 120 is located in the plurality of first portions 120a of the plurality of second defect density regions DR2 The two portions 120b each have a second dopant metal concentration, and the first dopant metal concentration is higher than the second dopant metal concentration. It is worth mentioning that, since the number of the plurality of first defect density regions DR1 (or the three-dimensional patterns 52 of the patterned substrate 50 ) arranged in the direction X of the epitaxial structure 100 is at least ten, the The distribution of dislocation defects is relatively regular and uniform, so that most of the doped metal DM can be evenly dispersed in the plurality of first defect density regions DR1. Accordingly, the uniformity of light output of the light emitting element 10 can be improved.

It should be noted that the number of epitaxial structures 100 (or light-emitting elements) formed on the patterned substrate 50 in this embodiment is exemplified by one example, but the invention is not limited thereto. In other embodiments, more than two epitaxial structures 100 (or light emitting elements) may also be formed on the patterned substrate, as long as the number of three-dimensional patterns 52 overlapped by each epitaxial structure 100 is at least ten or more. For example, in one embodiment, the number of the three-dimensional patterns 52 on the patterned substrate is more than 10 ⁴ , and the three-dimensional patterns 52 are arranged on the substrate 51 with a nano-scale pitch. That is to say, a maximum of 10 ³ epitaxial structures 100 can be fabricated on the patterned substrate, and each epitaxial structure 100 has at least ten first defect density regions DR1 and has relatively regular and uniform dislocation defects distribution, which helps to reduce the difference in emission wavelength among these epitaxial structures 100 . That is, the emission wavelengths of the epitaxial structures 100 (or light-emitting elements) fabricated by using the patterned substrate can have better uniformity, which is helpful to improve the color rendering of the light-emitting element structures using the epitaxial structures 100 uniformity.

Referring to FIGS. 1 and 3 , the light-emitting element 10 can also be removed from the patterned substrate 50 to become an independent component. At this time, the first surface 100 s 1 of the epitaxial structure 100 is provided with a plurality of three-dimensional patterns 111 separated from each other, and these three-dimensional patterns 111 are integrally formed with the epitaxial structure 100 . In this embodiment, the three-dimensional patterns 111 are recessed structures recessed into the first type semiconductor layer 110 from the first surface 100s1. It should be understood that these three-dimensional patterns 111 may correspond to a plurality of three-dimensional patterns 52 of the patterned substrate 50 , and the roughness of the first surface 100s1 is greater than that of the second surface 100s2. More specifically, the first surface 100s1 of the epitaxial structure 100 may be a rough surface, and the second surface 100s2 may be a flat surface. Accordingly, the light extraction efficiency and light extraction concentration of the light emitting element 10 can be increased.

4A is a schematic perspective view of a partial area of a patterned substrate according to another embodiment of the present invention. 4B is a schematic perspective view of a partial area of a patterned substrate according to another embodiment of the present invention. Referring to FIG. 4A , the main difference between the patterned substrate 50A of the present embodiment and the patterned substrate 50 of FIG. 1 is that the configurations of the three-dimensional patterns are different. In this embodiment, the outer contour of the three-dimensional pattern 52A is, for example, a cone, and the configuration of the cone enables the epitaxial structure formed on the patterned substrate 50A subsequently to have better light extraction efficiency and light extraction type. However, the present invention is not limited thereto, and according to other embodiments, the outer contour of the three-dimensional pattern 52B of the patterned substrate 50B may also be a cylinder (as shown in FIG. 4B ). In other unillustrated embodiments, the outer contour of the three-dimensional pattern can also be selected from polygonal cylinders, polygonal pyramids, other suitable configurations or combinations thereof, which are not limited herein.

In this embodiment, a plurality of three-dimensional patterns 52A are arrayed on the substrate 51 . More specifically, the three-dimensional patterns 52A are arranged on the substrate 51 along the direction X1 , the direction X2 and the direction X3 respectively (that is, the three-dimensional patterns 52A are distributed on the substrate 51 in the most dense arrangement). However, the present invention is not limited thereto, and according to other embodiments, the plurality of three-dimensional patterns 52A may also be arranged on the substrate 51 in two directions or four directions.

5 is a schematic cross-sectional view of a light-emitting element according to another embodiment of the present invention. Referring to FIG. 5 , the difference between the light-emitting element 10A of the present embodiment and the light-emitting element 10 of FIG. 3 lies in the composition of the light-emitting element. In this embodiment, the light-emitting element 10A further includes an insulating layer 160 . The insulating layer 160 covers a part of the surface of the epitaxial structure 100 and exposes the first surface 100s1, and the first electrode 151 and the second electrode 152 penetrate through the insulating layer 160 to electrically connect the first type semiconductor layer 110 and the second type semiconductor layer respectively. 130.

FIG. 6 is a schematic cross-sectional view of a light-emitting element according to another embodiment of the present invention. Referring to FIG. 6 , the main difference between the light-emitting element 11 of this embodiment and the light-emitting element 10 of FIG. 3 is that the electrodes are arranged differently. In this embodiment, the first electrode 151A and the second electrode 152 of the light-emitting element 11 are disposed on opposite sides of the epitaxial structure 100A. More specifically, the light emitting element 11 of the present embodiment may be a vertical type micro light emitting diode element. In detail, the first electrode 151A is formed on the first surface 100s1 and filled in the plurality of three-dimensional patterns 111 of the epitaxial structure 100A, so as to be electrically connected to the first type semiconductor layer 110 . More specifically, the upper surface 151As of the first electrode 151A is conformal to the first surface 100s1 of the epitaxial structure 100A. That is, the contact surface between the first electrode 151A and the first surface 100s1 is a patterned surface.

7 is a schematic cross-sectional view of a light-emitting element according to still another embodiment of the present invention. Referring to FIG. 7 , the difference between the light-emitting element 12 of this embodiment and the light-emitting element 11 of FIG. 6 is that the surface configuration of the epitaxial structure is different. In this embodiment, the first surface 100s1R of the epitaxial structure 100B is not provided with the three-dimensional pattern 111 as shown in FIG. 6 , and the roughness of the first surface 100s1R is greater than that of the second surface 100s2 . More specifically, the first surface 100s1R of the epitaxial structure 100B may be a rough surface, and the second surface 100s2 may be a flat surface. Accordingly, the light extraction efficiency and light extraction concentration of the light-emitting element 12 can be increased.

For example, before forming the first electrode 151B of the light-emitting element 12 , a grinding step may be performed to remove the three-dimensional pattern 111 (as shown in FIG. 6 ) recessed into the first-type semiconductor layer 110 . Next, the polished surface is roughened to form a first surface 100s1R of the epitaxial structure 100B, and a first electrode 151B is formed on the first surface 100s1R to electrically connect the first-type semiconductor layer 110A. As shown in FIG. 7 , in this embodiment, the upper surface 151Bs of the first electrode 151B is conformal to the first surface 100s1R of the epitaxial structure 100B. It should be noted that the roughness of the surface is defined by arithmetic mean roughness (Ra). However, the present invention is not limited thereto, and the definition of roughness can also be adjusted to root-mean-square roughness (Rq), ten-point average roughness (Rz), or other suitable definitions according to the structural characteristics of the surface. Way.

To sum up, in the epitaxial structure, the light-emitting element and the light-emitting element structure according to an embodiment of the present invention, the epitaxial structure has a plurality of alternately arranged first defect density regions and second defect density regions, and the first defect density The defect density of the region is lower than the defect density of the second defect density region. With the number of the first defect density regions being at least ten, the dislocation defects of the epitaxial structure can be distributed more regularly and uniformly, thereby improving the light emitting uniformity of the light emitting element and the color rendering uniformity of the light emitting element structure.

Although the present invention has been disclosed above with examples, it is not intended to limit the present invention. Any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to what is defined in the claims.

Claims (15)

1. A light emitting element structure, comprising:

the patterning substrate comprises a base material and a plurality of three-dimensional patterns, wherein the three-dimensional patterns and the base material are integrally formed, and the three-dimensional patterns are arranged on the base material in a mutually separated mode;

an epitaxial structure disposed on the patterned substrate and having a plurality of first defect density regions and a plurality of second defect density regions, wherein the plurality of first defect density regions respectively correspond to the plurality of three-dimensional patterns, the defect density of each first defect density region is lower than the defect density of each second defect density region, the number of spiral dislocation defects of each first defect density region is one or more, the number of spiral dislocation defects of each second defect density region is two or more, and the number of the plurality of first defect density regions is at least ten; and

the epitaxial structure further comprises a light emitting layer, a first type semiconductor layer and a second type semiconductor layer which are arranged on two opposite sides of the light emitting layer, and the first electrode and the second electrode are respectively and electrically connected with the first type semiconductor layer and the second type semiconductor layer.

2. The light-emitting element structure according to claim 1, wherein a ratio of a defect density of any of the second defect density regions to a defect density of any of the first defect density regions is 10 or more.

3. The light-emitting device structure according to claim 1, wherein each of the plurality of solid patterns has a base width and a height, and a ratio of the height to the base width is between 0.2 and 0.9.

4. The light-emitting element structure according to claim 1, wherein a space is provided between any two adjacent three-dimensional patterns, and the space is less than or equal to 0.5 μm.

5. The light-emitting element structure according to claim 1, wherein each of the solid patterns is a convex structure.

6. The light-emitting element structure according to claim 1, wherein the light-emitting layer comprises:

a plurality of first portions located at the plurality of first defect density regions; and

a plurality of second portions located in the plurality of second defect density regions, wherein the plurality of first portions have a first thickness, the plurality of second portions have a second thickness, and the first thickness is greater than the second thickness.

7. The light-emitting element structure according to claim 6, wherein each of the plurality of first portions has a first doped metal concentration, each of the plurality of second portions has a second doped metal concentration, and the first doped metal concentration is higher than the second doped metal concentration.

8. The light-emitting element structure according to claim 1, wherein the plurality of first defect density regions of the epitaxial structure are arranged in a number of at least ten in one direction.

9. The light-emitting element structure according to claim 8, wherein at least part of the plurality of first defect density regions and at least part of the plurality of second defect density regions are alternately arranged on the patterned substrate along the one direction.

10. The light-emitting device structure according to claim 1, wherein a space is formed between any two adjacent three-dimensional patterns, and the space is greater than 500 nm and less than or equal to 2500 nm.

11. A light-emitting element characterized by comprising:

the epitaxial structure is provided with a first surface and a second surface which are opposite to each other, and a plurality of first defect density areas and a plurality of second defect density areas;

a plurality of three-dimensional patterns integrally formed with the epitaxial structure and arranged on the first surface separately from each other, wherein the plurality of first defect density regions respectively correspond to the plurality of three-dimensional patterns, the defect density of each first defect density region is lower than the defect density of each second defect density region, the number of spiral dislocation defects of each first defect density region is one or more, the number of spiral dislocation defects of each second defect density region is two or more, and the number of the plurality of first defect density regions is at least ten; and

the epitaxial structure further comprises a light emitting layer, a first type semiconductor layer and a second type semiconductor layer which are arranged on two opposite sides of the light emitting layer, and the first electrode and the second electrode are respectively and electrically connected with the first type semiconductor layer and the second type semiconductor layer.

12. The light-emitting element according to claim 11, wherein the first electrode and the second electrode are electrically connected to the epitaxial structure through the first surface and the second surface, respectively, wherein an upper surface of the first electrode is conformal to the first surface of the epitaxial structure.

13. The light-emitting element according to claim 11, wherein roughness of the first surface of the epitaxial structure is larger than roughness of the second surface of the epitaxial structure.

14. The light-emitting element according to claim 11, wherein each of the three-dimensional patterns is a recessed structure.

15. A light-emitting element characterized by comprising:

an epitaxial structure having a first surface and a second surface opposite to each other, a plurality of first defect density regions and a plurality of second defect density regions, wherein the plurality of first defect density regions and the plurality of second defect density regions are alternately arranged between the first surface and the second surface along one direction, wherein a defect density of each of the first defect density regions is lower than a defect density of each of the second defect density regions, a number of spiral dislocation defects of each of the first defect density regions is one or more, a number of spiral dislocation defects of each of the second defect density regions is two or more, and a number of the plurality of first defect density regions is at least ten; and

the epitaxial structure further comprises a light emitting layer, a first type semiconductor layer and a second type semiconductor layer which are arranged on two opposite sides of the light emitting layer, and the first electrode and the second electrode are respectively and electrically connected with the first type semiconductor layer and the second type semiconductor layer.

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