A semiconductor light emitting element

Abstract

A semiconductor light emitting element includes a semiconductor light emitting sequence including a first type conductive semiconductor layer, a second type conductive semiconductor layer, and a light emitting layer between the two layers in a thickness direction; a plurality of finger electrodes on one side of the semiconductor light emitting sequence in the thickness direction; and a plurality of ohmic contact regions on the side opposite to the semiconductor light emitting sequence from the finger electrodes, the plurality of ohmic contact regions being arranged in a plurality of columns in a direction in which the finger electrodes extend between every two adjacent finger electrodes, wherein a distance between an arbitrary ohmic contact region (A) of a first column closest to the finger electrodes and an ohmic contact region (B) of the same column is greater than a distance between the arbitrary ohmic contact region (A) and an adjacent ohmic contact region (C) of a second column closest to the finger electrodes, and the plurality of ohmic contact regions of the adjacent two columns are arranged in a staggered manner in a direction perpendicular to the finger electrodes.

Description

Technical Field

[0001] This invention relates to a semiconductor light-emitting element. Background Technology

[0002] LEDs consist of a first type of conductive semiconductor layer (N-type doped), a light-emitting layer, and a second type of conductive semiconductor layer (P-type doped). How current spread occurs between the first and second types of conductive semiconductor layers is a key factor affecting internal quantum efficiency. Current main improvement methods include laterally placing extended electrodes on the main current injection electrode side to increase the injection current area and improve the uniformity of the injection current, or placing electrodes between the electrodes and the semiconductor sequence in an insulating layer and forming multiple ohmic contact regions on the insulating layer to improve current spread from the electrode to the semiconductor sequence side. The positional relationship of the extended electrodes or the multiple ohmic contact regions of the insulating layer openings also significantly affects the efficiency of current spread and transmission. Summary of the Invention

[0003] This invention provides a semiconductor light-emitting element comprising a semiconductor light-emitting sequence, the semiconductor light-emitting sequence including a first type of conductive semiconductor layer, a second type of conductive semiconductor layer, and a light-emitting layer between the two along the thickness direction; a plurality of finger electrodes located on one side of the semiconductor light-emitting sequence along the thickness direction; and a plurality of ohmic contact regions located on the opposite side of the semiconductor light-emitting sequence from the plurality of finger electrodes. The invention is characterized in that, viewed from the side where the plurality of finger electrodes of the semiconductor light-emitting sequence are located, the plurality of ohmic contact regions between every two adjacent finger electrodes are arranged in multiple columns along the direction of extension of the finger electrodes. The distance between any ohmic contact region (A) in the first column closest to a finger electrode and an adjacent ohmic contact region (B) in the same column is greater than the distance between any ohmic contact region (A) and an adjacent ohmic contact region (C) in the second column closest to the finger electrode. The plurality of ohmic contact regions in adjacent columns are staggered in a direction perpendicular to the finger electrodes.

[0004] More preferably, the main portions of the plurality of finger electrodes are parallel to each other; more preferably, the plurality of ohmic contact regions are arranged in multiple columns along the extension direction between the portions of the plurality of finger electrodes that extend parallel to each other.

[0005] More preferably, the plurality of contact areas are arranged in an array.

[0006] More preferably, there are four equidistant ohmic contact areas around any ohmic contact area in a row that is not closest to the finger electrodes.

[0007] More preferably, the four equidistant ohmic contact areas form a right-angled square structure.

[0008] More preferably, the arrangement of the plurality of contact areas is such that there are six ohmic contact areas equidistantly around one contact area.

[0009] More preferably, when viewed along the extension direction perpendicular to the finger electrode, an adjacent ohmic contact region (C) of the second column is located between two adjacent second ohmic contact regions (A) and (B) of the column closest to the finger electrode.

[0010] More preferably, the distance between any ohmic contact area (A) and an adjacent ohmic contact area (C) in an adjacent column is greater than or equal to twice the distance between the two adjacent columns.

[0011] More preferably, when viewed from the thickness direction of the semiconductor light-emitting sequence, the multiple finger electrodes do not overlap with the multiple ohmic contact regions.

[0012] More preferably, the distance between any one contact area and the adjacent finger electrode is between 5% and 50% of the horizontal distance between the two adjacent finger electrodes, wherein the horizontal distance is the horizontal distance obtained from a top-down view of the semiconductor light-emitting sequence.

[0013] More preferably, multiple contact areas between each pair of adjacent finger electrodes are arranged in multiple columns along the direction of the finger electrodes, and the distance between any two adjacent columns is between 1 and 50 μm.

[0014] More preferably, the size of each of the plurality of ohmic contact regions is 1 to 50 μm.

[0015] More preferably, the plurality of ohmic contact regions occupy 3 to 50% of the area on the side adjacent to the semiconductor light-emitting sequence.

[0016] More preferably, the main extensions of each of the plurality of finger electrodes are arranged in parallel to each other.

[0017] More preferably, the plurality of finger electrodes include the same first electrode region, and the plurality of finger electrodes extend out from the first electrode region.

[0018] More preferably, the width of the plurality of finger electrodes is 1~20μm.

[0019] More preferably, an insulating layer is formed on the other side of the semiconductor sequence thickness direction, the insulating layer having multiple exposed regions that expose a portion of the semiconductor light-emitting sequence on the other side of the thickness direction, the multiple exposed regions being multiple ohmic contact regions.

[0020] More preferably, the insulating layer is magnesium fluoride, calcium fluoride, silicon oxide, or silicon nitride.

[0021] More preferably, the multiple exposed areas of the insulating layer are formed by multiple through holes, and the opening size of the multiple through holes on the other side of the semiconductor light-emitting sequence thickness direction is smaller than the opening size on the side away from the semiconductor light-emitting sequence.

[0022] More preferably, the insulating layer has a conductive layer on the side away from the semiconductor light-emitting sequence, and the conductive layer may include a specular reflective layer.

[0023] By setting the distance between any contact area closest to the column where the finger electrode is located in the extension direction and the adjacent contact area in the same column to be greater than the distance between the contact area and the adjacent contact area in the adjacent column, the lateral current spread of the finger electrode along both sides can be effectively improved. Attached Figure Description

[0024] Figure 1 The structure obtained after preparing the first ohmic contact layer on the semiconductor light-emitting sequence in the process method of Example 1;

[0025] Figure 2 The structure obtained after transferring the material to a temporary substrate and preparing the second ohmic contact layer is described in the process method of Example 1.

[0026] Figure 3 The structure obtained by fabricating an insulating layer, a transparent conductive layer, a reflective layer, and a bonding support substrate on the second ohmic contact layer in the process method of Example 1;

[0027] Figure 4 This is a schematic diagram of the semiconductor light-emitting element structure obtained in Example 1;

[0028] Figure 5 This is a top view of one side of the first ohmic contact layer of the semiconductor light-emitting element obtained in Example 1;

[0029] Figure 6 for Figure 5 A magnified schematic diagram of the structure within the dashed circle;

[0030] Figure 7 The structure obtained after preparing the first ohmic contact layer on the semiconductor light-emitting sequence in the process method of Example 2;

[0031] Figure 8 The structure obtained after transferring the material to a temporary substrate and preparing the second ohmic contact layer is shown in the process of Example 2.

[0032] Figure 9 This is a schematic diagram of the semiconductor light-emitting element structure in Example 2;

[0033] Figure 10 This is a top view of one side of the second ohmic contact layer of the semiconductor light-emitting element in Example 2;

[0034] Figure 11 for Figure 10 A magnified schematic diagram of the structure within the dashed circle;

[0035] Figure 12 This is a schematic diagram of the semiconductor light-emitting element structure in Example 3;

[0036] Figure 13 This is a top view of the first ohmic contact layer of the semiconductor light-emitting element obtained for comparison.

[0037] Figure 14 for Figure 13 A magnified schematic diagram of the structure within the dashed circle. Detailed Implementation

[0038] Example 1

[0039] like Figure 1-6 The diagram illustrates a structure manufactured using the manufacturing method of corresponding steps disclosed in Embodiment 1 of the present invention. A method for manufacturing an optoelectronic device according to the present invention includes the following steps:

[0040] First, it provides a semiconductor light-emitting sequence:

[0041] A growth substrate 101 is provided, such as a growth substrate used for MOCVD growth of semiconductor light-emitting sequences, the substrate including but not limited to germanium (Ge), gallium arsenide (GaAs), indium phosphide (InP), gallium phosphide (GaP), sapphire, silicon carbide (SiC), silicon (Si), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), glass, composites, diamond, CVD diamond, diamond-like carbon (DLC), etc.

[0042] The first window layer 101 is formed on the substrate containing at least one element from the group consisting of Al, Ga, In, As, P, and N, such as GaN, AlGaInP, or any other suitable material. The first window layer 111 is a layer of the same conductivity type as the material on the same side of the semiconductor light-emitting sequence, such as N-type or p-type Al. X Ga （1−X） InP, where 0 ≦ X ≦ 1h; or such as AlGaAs. The first window layer 111 has two opposing first surfaces, wherein the window layer on the first surface is closer to the substrate.

[0043] A transition layer can be selectively formed between the growth substrate and the first window layer, and the two material systems of the transition layer can serve as a buffer system (not shown in the figure). This is for a structure used in light-emitting diodes, where the two material systems of the transition layer are used to reduce lattice mismatch. Alternatively, the transition layer can be a single layer, multiple layers, or a structure combining two materials, or two separate transition structures. The material layers can be organic, inorganic, metallic, semiconductor, etc., and the structure can be a reflective layer, a thermally conductive layer, a conductive layer, an ohmic contact layer, a deformation-resistant layer, a stress-relieving layer, a stress-adjusting layer, an adhesive layer, a wavelength conversion layer, a mechanically fixed structure, an etch-stop layer, etc.

[0044] Next, a semiconductor light-emitting sequence is formed on the window layer 101, including at least a first semiconductor layer 103 having a first conductivity type, and a light-emitting layer 104 and a second semiconductor layer 105 having a second conductivity type. The first semiconductor layer and the second semiconductor layer 105 are either two single-layer structures or two multilayer structures ("multilayer" refers to two or more layers with different conductivity types). The first conductivity type and the second conductivity type respectively provide electrons or holes and are doped with different dopants. If the first semiconductor layer 103 and the second semiconductor layer 105 are semiconductor materials, such as Al... X Ga （1−X） InP, where 0 ≤ X ≤ 1, or such as AlGaAs; the first or second conductivity type can be P-type or N-type. As an example, the first window layer 103 has the same conductivity type as the first semiconductor layer, such as N-type. Additionally, the first window layer 101 can have a higher impurity concentration than the first semiconductor layer 103, thus exhibiting better conductivity. Other non-semiconductor materials, such as metals, oxide layers, insulating layers, etc., can also be selectively formed on the surface of the semiconductor light-emitting sequence.

[0045] The light-emitting layer 104 is formed by stacking a series of commonly used materials such as aluminum gallium indium phosphide (AlGaInP), aluminum indium gallium nitride (AlInGaN), or aluminum gallium arsenide (AlGaAs). Specifically, it is a single heterojunction, double heterojunction, or multi-quantum well structure, including an MQW structure comprising multiple barrier layers and well layers stacked alternately. Each barrier layer comprises AlyGa(1−y)InP, where 0 ≦y ≦1, and each well layer comprises AlzGa(1−z)InP, where 0 ≦z ≦1. Furthermore, the wavelength of the emitted light can be adjusted by changing the composition of the well or barrier layer composition by altering the number of quanta. For example, the dominant wavelength of the emitted light between 600 and 630 nm is red light with a y of approximately 0.7, or amber light between 580 and 600 nm with a y of approximately 0.55. The light-emitting layer 104 can provide light radiation in the ultraviolet to green range of 200-550nm, or light in the red, yellow, orange, amber, or infrared range of 550-950nm.

[0046] A second window layer 106 is formed on top of the semiconductor light-emitting sequence. It can serve as a current-spreading layer on the side of the second semiconductor layer 105. The material of the second window layer contains at least one material selected from the group consisting of Al, Ga, In, As, P, N, such as GaN, AlGaInP, or any other suitable material. The second window layer 106 includes at least one material different from that of the semiconductor light-emitting sequence. Preferably, the second window layer has the same conductivity type as the second semiconductor layer, such as a p-type GaP layer. As an example, the second window layer can be fabricated using the same process as the semiconductor sequence, or it can be part of the overall semiconductor light-emitting sequence.

[0047] Second, create the first ohmic contact layer on the second window:

[0048] Then, as Figure 1 As shown, the first ohmic contact layer 107 is formed of a conductive material such as a metal or a transparent inorganic oxide conductive material. The metal can be an alloy, specifically AuBe or AuGe, and can be a single layer or multiple layers of metal or alloy. The first ohmic contact layer is mainly used for ohmic contact and current spread between the electrode and the semiconductor light-emitting sequence side. The inorganic oxide conductive material can be ITO, IZO, or GZO, etc., and is placed on the second window layer 106. The first ohmic contact layer 107 is preferably, but not limited to, formed on the second semiconductor layer side by vapor deposition or chemical plating, and then alloyed at 300-500°C to form an alloyed contact layer between the first ohmic contact layer 107 and the second window layer. The details of the alloying process are well known to those skilled in the art and need not be disclosed herein.

[0049] Third, remove the growth substrate:

[0050] like Figure 2 As shown, a temporary substrate 108, such as glass, is bonded to the first ohmic contact layer 107 and the second window layer 106. The growth substrate 101 is then removed. The bonding agent can be a material that is easily removed by heating or solvent dissolution or decomposition, such as glue or resin. The bonding process is a conventional process. There are many ways to remove the growth substrate, and conventional methods can be selected according to the actual growth substrate, such as wet etching, dry etching, or grinding. The growth substrate is removed to expose the first window layer 102.

[0051] Fourth, a second ohmic contact layer, a reflective layer, and a support substrate are formed on the first window layer side:

[0052] A second ohmic contact layer 109 is formed on the first window layer 102. To ensure good electrical contact between the second ohmic contact layer 109 and the first window layer 102, the second ohmic contact layer 109 is preferably made of a metal, more preferably a metal alloy, such as AuGe or AuBe. The second ohmic contact layer 109 is formed on the first window layer 102 in the form of multiple ohmic contact regions and does not overlap with the first ohmic contact layer 107 in the thickness direction, thereby improving current spread between the first ohmic contact layer 107 and the second ohmic contact layer 109.

[0053] like Figure 3 As shown, a transparent insulating layer 110 is then formed on the surface of the second ohmic contact layer 109. The formation process of the transparent insulating layer 110 is preferably, but not limited to, electron beam or sputtering deposition. The material of the insulating layer 110 is an oxide, nitride, or fluoride, such as silicon dioxide, silicon nitride, calcium fluoride, or magnesium fluoride. The refractive index of the insulating layer 110 is between 1.3 and 1.6, and the refractive index of the insulating layer is at least 1.5 lower than that of the first window layer 102. The thickness of the insulating layer 110 is 50 to 500 nm, more preferably 50 to 100 nm. The insulating layer 110 is etched by BOE or RIE methods to expose the second ohmic contact layer 109 or may further expose a portion of the first window layer 102. Next, a transparent conductive layer 111 is formed on the surface of the second ohmic contact layer 109 and the insulating layer 110. This transparent conductive layer is a transparent conductive metal oxide, such as ITO, IZO, GZO, or CTO, and its thickness is preferably 5-15 nm. Then, a metal reflective layer 112 is formed on the transparent conductive layer 111, with the transparent conductive layer 111 acting as an adhesive between the metal reflective layers 112. The insulating layer 109 blocks current. When current flows through the second ohmic contact layer 109, the multiple locations of the second ohmic contact layer 109 have a current-spreading effect. Simultaneously, the insulating layer 110 and the metal reflective layer 112 can form an ODR structure, improving reflection efficiency; the reflectivity can reach over 95%.

[0054] The reflective layer 112 is bonded to the support substrate 113. The bonding process can be metal-to-metal high-temperature and high-pressure bonding. The composition of the metal-to-metal bond can be at least one of In, Au, Sn, Pb, InAu, and SnAu.

[0055] Next, the temporary substrate 108 is removed, exposing the first ohmic contact layer and the first window layer.

[0056] Fifth, remove the temporary substrate and fabricate the first and second electrodes:

[0057] like Figure 4As shown, a first electrode 1071 is formed on the first ohmic contact layer 107. The material of the first electrode 1071 is preferably a metal material that can be used for external bonding wires, and more preferably at least one of gold and aluminum. The first electrode 1071 connects one end of the finger electrodes of a plurality of first ohmic contact layers 1071, and the other end of the finger electrodes extends out to form a second electrode 114 on the back side of the support substrate 113. The second electrode is preferably a metal or metal alloy, such as Pt or Au.

[0058] The process involves dicing and separating the components to form chips of the appropriate size. To better protect the semiconductor light-emitting sequence and the second ohmic contact layer, an insulating protective layer is fabricated on the exposed sides and surfaces of the semiconductor light-emitting sequence and the surface of the second ohmic contact layer, thus completing the fabrication of a single chip. This single chip can then be transferred to subsequent packaging and application fabrication.

[0059] The positional relationship between the first ohmic contact layer and the second ohmic contact layer is explained in detail below. For example... Figure 5 As shown, the first ohmic contact layer 107 includes a plurality of finger electrodes extending horizontally on one side of the second window layer 106. The plurality of finger electrodes are connected to the first electrode 1071. Current is injected through the first electrode 1071 and extended through the plurality of finger electrodes and injected into the semiconductor light-emitting sequence. Then, it is transmitted longitudinally and laterally along the thickness direction of the semiconductor light-emitting sequence to a plurality of contact areas of the second ohmic contact layer and transmitted downward to the second electrode. Alternatively, current is transmitted from the second electrode to a plurality of contact areas of the second ohmic contact layer and further transmitted to the semiconductor light-emitting sequence. Then, it is transmitted to the first electrode through the plurality of finger electrodes of the first ohmic contact layer, thereby improving the uniformity of current transmission.

[0060] The small portion of each finger electrode connected to the first electrode can be curved, bent, or straight. To ensure the uniformity of current transmission on one side of the semiconductor sequence, it is preferable that the main portion of each finger electrode extends in parallel. Ideally, the parallelism can deviate from the parallelism by a maximum of about 10°, meaning that multiple finger electrodes can extend outwards with their main portions parallel to each other. The number of multiple finger electrodes is at least two, and the width of each finger electrode and the spacing between adjacent fingers can be conventionally designed according to the actual chip size. The width of the multiple finger electrodes can be constant along the direction of extension or vary according to the uniformity of current diffusion. For example, the width can gradually decrease along the extension direction, and the size of the portion of the finger electrode around the first electrode is larger than the size of the portion away from the first electrode. The width of the multiple finger electrodes is 1~50μm.

[0061] Viewed from the finger electrode side of the semiconductor light-emitting sequence, the second ohmic contact layer 107 between each pair of adjacent finger electrodes is arranged in a dotted pattern to form multiple second ohmic contact regions. These multiple second ohmic contact regions are arranged in multiple columns along the direction parallel to the finger electrodes. More preferably, the multiple finger electrodes do not overlap with the multiple second ohmic contact regions in the thickness direction to facilitate simultaneous current propagation in both the lateral and longitudinal directions. Even more preferably, the multiple second ohmic contact regions are arranged in an array on one side of the semiconductor light-emitting sequence. The array is formed by arranging a fixed number of second ohmic contact regions into a fixed unit and repeating the arrangement, specifically as follows: Figure 5 As shown, multiple second ohmic contact regions are arranged in a most compact hexagonal pattern, that is, each second ohmic contact region (excluding the multiple second ohmic contact regions in the row closest to the strip electrode) is surrounded by six equidistant second ohmic contact regions. Preferably, the size of each second ohmic contact region is 1~50μm, and each of the multiple second contact regions is circular, polygonal, or elliptical. The ratio between the total area of ​​the multiple ohmic contact regions and the area on one side of the semiconductor sequence is 3~50%.

[0062] Since the current is preferably transmitted along the shortest path (with the lowest resistance), the vertical distance between the multiple second ohmic contact areas in the first column closest to the finger electrode is the closest, while the multiple ohmic contact areas in the second column are much farther away from the finger electrode. The current is preferably transmitted from the direction perpendicular to the extension direction of the finger electrode to the multiple second ohmic areas closest to the first column on both sides. The current is more likely to be congested in the ohmic contact areas of the first column, resulting in excessive current concentration in the multiple second ohmic contact areas of the first column and uneven current transmission. Therefore, in order to ensure the uniformity of current transmission between the finger electrode and the second ohmic contact areas and to prevent the current from concentrating near the sides of the finger electrode, this invention is specially designed to place the second ohmic contact electrode as close as possible to the finger electrode, so that the distance from the finger electrode side to the multiple second ohmic contact areas of the second column is closer.

[0063] Specifically, such as Figure 6As shown, the distance between any second ohmic contact area A in the first column closest to the finger electrode and an adjacent second ohmic contact area B in the same column is greater than the distance between the second ohmic contact area A and an adjacent second ohmic contact area C in an adjacent column. Specifically, the distance between any second ohmic contact area A in the first column closest to the finger electrode and an adjacent second ohmic contact area B in the same column, parallel to the extension direction of the finger electrode, is defined as D1, where D1 ranges from 1 to 50 μm. The distance between any second ohmic contact area B in the first column closest to the finger electrode and an adjacent second ohmic contact area C in an adjacent column is D2, where D1 is greater than D2. This ensures that adjacent second ohmic contact areas C in adjacent columns are as close to the finger electrode as possible. More preferably, as shown... Figure 6 As shown, when multiple second ohmic contact regions are arranged in the closest hexagonal configuration, the ratio between D1 and D2 is: 1; More preferably, when viewed in the direction perpendicular to the finger electrode, any second ohmic contact region C in the second column is located between two adjacent second ohmic contact regions A and B in the first column. That is, when viewed in the direction perpendicular to the finger electrode, the second ohmic contact region C is staggered or spaced apart from the two second ohmic contact regions A and B in the first column. In other words, the line connecting the second contact region C and the second contact regions A and B is not perpendicular to the finger electrode. This ensures that a portion of the current from the finger electrode will flow more easily to the second contact region C, reducing the proportion of current concentrated in multiple second ohmic contact regions in the first column. More preferably, the distance between two adjacent columns is half the value of D2.

[0064] More preferably, the distance between two adjacent second ohmic contact areas in any column is defined as a unit D3, and the distance between any second ohmic contact area and an adjacent second ohmic contact area in an adjacent column is less than this unit D4, where D3=D1 and D4=D2.

[0065] To ensure good current propagation between the finger electrode and the second ohmic contact area, the distance between any second ohmic contact area in the first column closest to the finger electrode and the finger electrode, which is parallel to the extension direction of the finger electrode, is 5% to 50% of the horizontal distance between two adjacent finger electrodes. Conversely, if the distance between multiple second ohmic contact areas in the first column and the finger electrode is too close, it will cause the current to be excessively concentrated in the multiple second ohmic contact areas in the first column, which is not conducive to the lateral transmission of the current.

[0066] Example 2

[0067] The fabrication process differs from that of Example 1 in that a second ohmic contact layer 201, such as a metal alloy, such as an AuBe or AuGe alloy, is formed on the second window layer 106 on the light-emitting semiconductor sequence fabricated in the first step, thereby forming a... Figure 7 The structure is shown. The second ohmic contact layer 201 comprises multiple independent ohmic contact regions, horizontally distributed along one side of the second window layer 106. Then, an alloying treatment is performed at 300-500°C to form an alloyed contact layer between the second ohmic contact layer 201 and the second window layer 106 for forming the ohmic contact. Details of the alloying process are well known to those skilled in the art and need not be disclosed herein.

[0068] like Figure 8 As shown, a transparent insulating layer 202 is formed on the surface of the second ohmic contact layer 201. The transparent insulating layer 202 is formed by electron beam deposition or sputtering. The material of the insulating layer 202 is an oxide, nitride, or fluoride, such as silicon dioxide, silicon nitride, calcium fluoride, or magnesium fluoride. The refractive index of the insulating layer 202 is between 1.3 and 1.6, and the refractive index of the insulating layer is at least 1.5 lower than that of the first window layer. The thickness of the insulating layer 202 is 50-500 nm, more preferably 50-100 nm. The insulating layer 202 is etched by BOE or RIE methods to expose the second ohmic contact layer 201 or to further expose a portion of the second window layer 201.

[0069] Next, a transparent conductive layer 203 is formed on the surface of the second ohmic contact layer 201 and the insulating layer 202. The transparent conductive layer 203 is a transparent conductive metal oxide, such as ITO, IZO, GZO, or CTO, and its thickness is 5~500 nm. Then, a metal reflective layer 204 is formed on the transparent conductive layer 203, which acts as an adhesive between the metal reflective layers. The insulating layer 202 blocks current. When current flows through the second ohmic contact layer, the multiple first ohmic contact layers have a current spreading effect. At the same time, the insulating layer 203 and the reflective layer 204 can form an ODR structure, improving the reflection efficiency. The reflectivity can reach over 95%. The reflective layer can be made of a metal material with high reflectivity, such as silver or gold.

[0070] The reflective layer 204 is then bonded to the support substrate 205. The bonding process can be metal-to-metal high-temperature and high-pressure bonding. The composition of the metal-to-metal bond can be at least one of In, Au, Sn, Pb, InAu, and SnAu.

[0071] Next, the growth substrate 101 is removed to expose the first window layer 102.

[0072] Next, a first ohmic contact layer 207, such as a conductive material like an AuBe or AuGe alloy, is formed on the first window layer 102. The first ohmic contact layer 107 is preferably, but not limited to, formed on the second semiconductor layer side by vapor deposition or chemical plating, and then alloyed at 300-500°C to form an alloyed contact layer between the first ohmic contact layer 107 and the first window layer 102 for forming the ohmic contact. Details of the alloying process are well known to those skilled in the art and need not be disclosed herein.

[0073] Then a first electrode 2071 is formed on the first ohmic contact layer 207. The first electrode 2071 is used for external electrical connection. A second electrode 206 is formed on the back side of the support substrate 205.

[0074] Specifically, the first ohmic contact layer 207 includes a plurality of finger electrodes extending horizontally on one side of the second window layer. The plurality of finger electrodes are connected to the first electrode 2071. Current is injected through the first electrode 2071 and spread through the plurality of finger electrodes. Then, it is transmitted longitudinally and laterally along the thickness direction of the semiconductor light-emitting sequence to a plurality of contact areas of the second ohmic contact layer and transmitted downward to the second electrode 206. Alternatively, current is transmitted from the second electrode 206 to a plurality of contact areas of the second ohmic contact layer and further transmitted to the semiconductor light-emitting sequence. Then, it is transmitted to the first electrode through the plurality of finger electrodes of the first ohmic contact layer.

[0075] The small portion near the connection between each finger electrode and the first electrode can be curved, bent, or straight. To ensure the uniformity of current transmission on one side of the semiconductor sequence, it is preferable that the main portion of each finger electrode is as parallel as possible, i.e., multiple finger electrodes can extend outwards with their main portions parallel to each other. The width of each finger electrode and the spacing between adjacent fingers can be conventionally designed according to the actual chip size. The width of the multiple finger electrodes can be constant along the direction of extension or vary according to the uniformity of current diffusion, such as gradually decreasing the width along the extension direction. The size of the portion of the finger electrode around the first electrode is larger than the size of the portion away from the first electrode. The width of the multiple finger electrodes is 1~20μm.

[0076] Viewed from the thickness direction of the semiconductor light-emitting sequence, the second ohmic contact layer 201 between each pair of adjacent finger electrodes is arranged in a dotted manner to form multiple second ohmic contact regions. These multiple second ohmic contact regions are arranged in multiple columns along the direction parallel to the finger electrodes. The multiple finger electrodes do not overlap with the multiple second ohmic contact regions in the thickness direction. The multiple second ohmic contact regions are arranged in an array on one side of the semiconductor light-emitting sequence. This array is formed by arranging several second ohmic contact regions in a repeating unit configuration, as specifically in this embodiment or as in... Figure 10-11 As shown, the distance between any ohmic contact region A' in the first column closest to the finger electrode and an adjacent ohmic contact region B' in the same column is greater than the distance between any ohmic contact region A' and an adjacent ohmic contact region C' in the second column closest to the finger electrode. Multiple ohmic contact regions in adjacent columns are staggered in a direction perpendicular to the finger electrode. More preferably, the ratio between the distance between any ohmic contact region (A, A') in the first column closest to the finger electrode and an adjacent ohmic contact region (B, B') in the same column and the distance between any ohmic contact region (A, A') and an adjacent ohmic contact region (C, C') in the second column closest to the finger electrode is greater than [a certain value]. Multiple ohmic contact regions in two adjacent columns are staggered in a direction perpendicular to the finger electrodes. The multiple second ohmic contact regions are arranged in a square array, meaning that any ohmic contact region C' in any column other than the one closest to the finger electrode is surrounded by four equidistant ohmic contact regions (including A' and B'), located at the four corners of a square, which can be either a square or a rectangle. The size of each second ohmic contact region is 1~50 μm. Each of the multiple second contact regions is circular, polygonal, or elliptical. The ratio between the total area of ​​the multiple ohmic contact regions and the area on one side of the semiconductor sequence is 3~50%. More preferably, the distance between any ohmic contact region (A) and an adjacent ohmic contact region (C) in an adjacent column is greater than twice the distance between two adjacent columns.

[0077] Example 3

[0078] like Figure 12 The structure shown differs from Embodiment 2 in that an insulating layer 301 is first formed on the second window layer 106. The transparent insulating layer 301 is formed by electron beam or sputtering deposition. The material of the insulating layer 301 is an oxide, nitride, or fluoride, such as silicon dioxide, silicon nitride, calcium fluoride, or magnesium fluoride. The refractive index of the insulating layer is between 1.3 and 1.6, and the refractive index of the insulating layer 301 is at least 1.5 lower than that of the first window layer 106. The thickness of the insulating layer 301 is 50-500 nm, more preferably 50-100 nm. The insulating layer 301 is etched by BOE or RIE to expose a portion of the first window layer, forming multiple tiny through-holes in the insulating layer 301. The size of each through-hole is 1-50 μm, and the percentage of the multiple through-holes occupying one side of the second window layer 106 or the semiconductor light-emitting sequence is 10-50%.

[0079] A transparent conductive layer 302, such as ITO, IZO, GZO, or CTO, is further fabricated in the multiple through-holes exposed on the side of the second window layer 106 and on the surface of the insulating layer 301. The thickness of the transparent conductive layer 302 is 5~5000nm, and the transparent conductive layer can be formed by a single layer or multiple layers of different materials. Multiple ohmic contact areas are formed between the transparent conductive layer 302 and the second window layer 106, and then a metal reflective layer 303 is formed on the transparent conductive layer 302. The bonding of the support substrate 304 and subsequent fabrication processes are the same as in Example 2.

[0080] Next, a first ohmic contact layer 307, such as a conductive material like an AuBe or AuGe alloy, is formed on the first window layer 102. The first ohmic contact layer 307 is preferably, but not limited to, formed on the second semiconductor layer side by vapor deposition or chemical plating, and then alloyed at 300-500°C to form an alloyed contact layer between the first ohmic contact layer 307 and the first window layer 102 for forming the ohmic contact. Details of the alloying process are well known to those skilled in the art and need not be disclosed herein.

[0081] Then a first electrode 3071 is formed on the first ohmic contact layer 307. The first electrode 3071 is used for external electrical connection. A second electrode 305 is formed on the back side of the support substrate 205.

[0082] The positional relationship between the finger electrodes of the first ohmic contact layer 307 and the multiple ohmic contact areas of the transparent conductive layer 302 is the same as that in Embodiment 1.

[0083] Comparative Example 1

[0084] The materials of each layer of the light-emitting element are arranged in the same manner as in Example 1, and as follows: Figure 13 As shown, in this comparative example, the plurality of second ohmic contact regions are arranged in a densest hexagonal pattern, meaning that any one of the second ohmic contact regions is surrounded by six equidistant ohmic contact regions. Unlike Example 1, as... Figure 14 As shown, the distance between multiple contact areas A'' and B'' is equal to the distance between ohmic contact areas B'' and C''. Based on this arrangement, unlike... Figure 5 and Figure 6 The distance between ohmic contact regions A and B is greater than the distance between ohmic contact regions B and C. According to this arrangement, since the multiple adjacent ohmic contact regions in the second column near the finger electrodes are far away from the finger electrodes, the current will preferably concentrate between two adjacent second ohmic contact regions near the first column. This makes it easier for the current to crowd into the multiple second ohmic contact regions in the first column, making it more difficult for the lateral current to diffuse between the finger electrodes, resulting in uneven diffusion.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A semiconductor light-emitting element, comprising: A semiconductor light-emitting sequence, comprising a first type of conductive semiconductor layer, a second type of conductive semiconductor layer, and a light-emitting layer between the two; Multiple finger electrodes are located on one side of the semiconductor light-emitting sequence along its thickness; multiple ohmic contact regions are located on the opposite side of the semiconductor light-emitting sequence, opposite to the multiple finger electrodes. The feature is that the main portions of the multiple finger electrodes are parallel to each other. Viewed from the side where the multiple finger electrodes of the semiconductor light-emitting sequence are located, the multiple ohmic contact regions between the main portions of every two adjacent parallel finger electrodes are arranged in multiple columns along the direction extending from the main portions of the parallel finger electrodes. Any ohmic contact region (A, A') in the first column closest to the main portion of one of the finger electrodes is connected to an adjacent ohmic contact region (B, B') in the same column. The distance between them is greater than the distance between any one of the ohmic contact areas (A, A') and an adjacent ohmic contact area (C, C') in the second column of the main part closest to the finger electrode. Multiple ohmic contact areas in adjacent columns are staggered in the direction of extension of the main part, which is perpendicular to the finger electrode and parallel to each other. These multiple ohmic contact areas are arranged in an array, where each ohmic contact area is surrounded by four equally spaced ohmic contact areas. The ratio between the distance between any one ohmic contact area (A, A') in the first column closest to the finger electrode and an adjacent ohmic contact area (B, B') in the same column and the distance between any one ohmic contact area (A, A') and an adjacent ohmic contact area (C, C') in the second column closest to the finger electrode is greater than or equal to the distance between them. :

1. Multiple ohmic contact areas in two adjacent columns are staggered in a direction perpendicular to the finger electrodes.

2. A semiconductor light-emitting element according to claim 1, characterized in that: The four equidistant ohmic contact areas form a right-angled square.

3. A semiconductor light-emitting element according to claim 1, characterized in that: Looking along the direction perpendicular to the extension of the finger electrode, the adjacent ohmic contact region (C, C') of the second column is located between the two adjacent second ohmic contact regions (A, A') and (B, B') of the column closest to the finger electrode.

4. A semiconductor light-emitting element according to claim 1, characterized in that: The distance between any ohmic contact region (A, A') and an adjacent ohmic contact region (C, C') in an adjacent column is greater than or equal to twice the distance between the two adjacent columns.

5. A semiconductor light-emitting element according to claim 1, characterized in that: Looking at the thickness direction of the semiconductor light-emitting sequence, multiple finger electrodes do not overlap with multiple ohmic contact areas.

6. A semiconductor light-emitting element according to claim 1, characterized in that: The multiple finger electrodes are connected to the same first electrode region, and the multiple finger electrodes extend out from the first electrode region.

7. A semiconductor light-emitting element according to claim 1, characterized in that: An insulating layer is formed on the side opposite to the finger electrode in the thickness direction of the semiconductor light-emitting sequence. The insulating layer has multiple exposed regions that expose portions of the semiconductor light-emitting sequence, and the multiple exposed regions are multiple ohmic contact regions.

8. A semiconductor light-emitting element according to claim 7, characterized in that: The multiple exposed areas of the insulating layer are formed by multiple through holes, and the opening size of the multiple through holes on the semiconductor light-emitting sequence side is smaller than the opening size away from the semiconductor light-emitting sequence side.

9. The semiconductor light-emitting element according to claim 7, characterized in that: The insulating layer has a conductive layer on the side away from the semiconductor light-emitting sequence, and the conductive layer includes a specular reflective layer.

10. The semiconductor light-emitting element according to claim 1, characterized in that: The distance between any two adjacent ohmic contact areas in any column is greater than the distance between any ohmic contact area and the adjacent second ohmic contact area in the adjacent column.

11. A semiconductor light-emitting element, comprising: A semiconductor light-emitting sequence, comprising a first type of conductive semiconductor layer, a second type of conductive semiconductor layer, and a light-emitting layer between the two; Multiple finger electrodes are located on one side of the semiconductor light-emitting sequence along its thickness; multiple ohmic contact regions are located on the opposite side of the semiconductor light-emitting sequence, opposite to the multiple finger electrodes. The feature is that the main portions of the multiple finger electrodes are parallel to each other. Viewed from the side where the multiple finger electrodes of the semiconductor light-emitting sequence are located, the multiple ohmic contact regions between the main portions of every two adjacent parallel finger electrodes are arranged in multiple columns along the direction extending from the main portions of the parallel finger electrodes. Any ohmic contact region (A, A') in the first column closest to the main portion of one of the finger electrodes is connected to an adjacent ohmic contact region (B, B') in the same column. The distance between them is greater than the distance between any one of the ohmic contact areas (A, A') and an adjacent ohmic contact area (C, C') in the second column of the main part near the finger electrode. The multiple ohmic contact areas in the two adjacent columns are staggered in the extension direction of the main part that is perpendicular to the finger electrode and parallel to each other. The multiple ohmic contact areas are arranged in an array. The array arrangement is such that any one ohmic contact area is surrounded by four equidistant ohmic contact areas, and the four equidistant ohmic contact areas form a rectangle.

12. A semiconductor light-emitting element according to claim 11, characterized in that: The ratio between the distance between any ohmic contact region (A, A') in the first column closest to the finger electrode and an adjacent ohmic contact region (B, B') in the same column and the distance between any ohmic contact region (A, A') and an adjacent ohmic contact region (C, C') in the second column closest to the finger electrode is greater than or equal to the following: :

1. Multiple ohmic contact areas in two adjacent columns are staggered in a direction perpendicular to the finger electrodes.

13. A semiconductor light-emitting element according to claim 12, characterized in that: Looking along the direction perpendicular to the extension of the finger electrode, the adjacent ohmic contact region (C, C') of the second column is located between the two adjacent second ohmic contact regions (A, A') and (B, B') of the column closest to the finger electrode.

14. A semiconductor light-emitting element according to claim 12, characterized in that: The distance between any ohmic contact region (A, A') and an adjacent ohmic contact region (C, C') in an adjacent column is greater than or equal to twice the distance between the two adjacent columns.

15. A semiconductor light-emitting element according to claim 12, characterized in that: Looking at the thickness direction of the semiconductor light-emitting sequence, multiple finger electrodes do not overlap with multiple ohmic contact areas.

16. A semiconductor light-emitting element according to claim 12, characterized in that: The multiple finger electrodes are connected to the same first electrode region, and the multiple finger electrodes extend out from the first electrode region.

17. A semiconductor light-emitting element according to claim 12, characterized in that: An insulating layer is formed on the side opposite to the finger electrode in the thickness direction of the semiconductor light-emitting sequence. The insulating layer has multiple exposed regions that expose portions of the semiconductor light-emitting sequence, and the multiple exposed regions are multiple ohmic contact regions.

18. A semiconductor light-emitting element according to claim 17, characterized in that: The multiple exposed areas of the insulating layer are formed by multiple through holes, and the opening size of the multiple through holes on the semiconductor light-emitting sequence side is smaller than the opening size away from the semiconductor light-emitting sequence side.

19. The semiconductor light-emitting element according to claim 17, characterized in that: The insulating layer has a conductive layer on the side away from the semiconductor light-emitting sequence, and the conductive layer includes a specular reflective layer.

20. The semiconductor light-emitting element according to claim 12, characterized in that: The distance between any two adjacent ohmic contact areas in any column is greater than the distance between any ohmic contact area and the adjacent second ohmic contact area in the adjacent column.

Images