Semiconductor light-emitting device and preparation method thereof
By connecting multiple LED epitaxial structures with a small number of CRD epitaxial structures in series in a semiconductor light emitting device, the problem of uneven brightness of the head and tail of the LED light band is solved, and the brightness uniformity and volume reduction are achieved.
Patent Information
- Application Number
- CN202411943258.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-04-11
AI Technical Summary
The LED light strip may have an uneven luminance in the head and tail part, and the prior art is difficult to effectively solve this problem.
A semiconductor light emitting device is designed, by providing multiple LED epitaxial structures and a small number of CRD epitaxial structures on the same substrate, the LED and CRD epitaxial structures are connected in series with internal circuits to improve the uniformity of luminous luminance.
The uniformity of the luminous brightness of the head and tail of the LED light band is achieved, reducing the overall volume of the device, and improving the uniformity of current and luminous efficiency.
Smart Images
Figure CN119816058A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor light emitting technology, and in particular to a semiconductor light emitting device and a preparation method thereof. Background Art
[0002] LED (light-emitting diode) has the advantages of energy saving, small size, good shock resistance, environmental protection, long life, various light colors, fast response, etc. It is widely used in lighting, automobiles, transportation, billboards, instrument indicator lights and other fields. LED light strips were born with the development of LED technology. They can be cut according to the actual length, which is very convenient. There are multiple light colors such as red, green, blue, yellow-white, warm white, etc. Now it basically replaces LED tubes. However, LED light strips may have uneven brightness at the head and tail, so it is necessary to improve the LED chip to improve the problem of uneven brightness at the head and tail of LED light strips. Summary of the invention
[0003] Therefore, in order to overcome at least some of the defects in the prior art, an embodiment of the present invention provides a semiconductor light-emitting device and a method for preparing the same, which combines the characteristics of LED and CRD chips, can improve the problem of uneven brightness at the head and tail of LED light strips, and has a smaller volume.
[0004] Specifically, on the one hand, an embodiment of the present invention provides a semiconductor light-emitting device, comprising: a substrate; an LED epitaxial structure, comprising an N-type semiconductor layer, a quantum well layer and a P-type semiconductor layer sequentially arranged on the substrate; the number of the LED epitaxial structures is multiple, and the multiple LED epitaxial structures are spaced apart from each other; a CRD epitaxial structure, arranged on the side of the substrate facing the LED epitaxial structure and spaced apart from the LED epitaxial structure, the CRD epitaxial structure comprising a first buffer layer, a first high-resistance buffer layer, a channel layer, an isolation layer and a barrier layer sequentially arranged on the substrate; the first buffer layer contains AlN, and the first high-resistance buffer layer contains GaN; the number of the LED epitaxial structures is greater than the number of the CRD epitaxial structures.
[0005] Another embodiment of the present invention provides a method for preparing a semiconductor light-emitting device, comprising:
[0006] S1: growing a first epitaxial structure material layer on a substrate;
[0007] S2: forming a growth inhibition layer on a side of the first epitaxial structure material layer away from the substrate;
[0008] S3: etching a portion of the first epitaxial structure material layer to obtain a first epitaxial structure disposed on a partial region of the substrate;
[0009] S4: growing a second epitaxial structure material layer on the substrate in an area exposed outside the first epitaxial structure;
[0010] S5: etching the junction between the second epitaxial structure material layer and the first epitaxial structure to obtain a first epitaxial structure and a second epitaxial structure spaced apart from each other;
[0011] One of the first epitaxial structure and the second epitaxial structure is an LED epitaxial structure, comprising an N-type semiconductor layer, a quantum well layer and a P-type semiconductor layer sequentially arranged on the substrate; the other is a CRD epitaxial structure, comprising a first buffer layer, a first high-resistance buffer layer, a channel layer, an isolation layer and a barrier layer sequentially arranged on the substrate; the first buffer layer contains AlN, and the first high-resistance buffer layer contains GaN;
[0012] There are multiple LED epitaxial structures, and the multiple LED epitaxial structures are arranged at intervals from each other; and the number of the LED epitaxial structures is greater than the number of the CRD epitaxial structures.
[0013] As can be seen from the above, the above embodiments of the present invention can achieve one or more of the following beneficial effects: the LED epitaxial structure and the CRD epitaxial structure in the semiconductor light-emitting device are arranged on the same substrate, and the LED epitaxial structure makes it have the characteristics of LED light emission when powered on, and the CRD epitaxial structure makes it have the characteristics of constant current diode constant current and high voltage resistance when powered on, so that the semiconductor light-emitting device is equivalent to integrating the functions of LED chip and CRD chip in one, and the LED epitaxial structure and the CRD epitaxial structure can be connected in series through the internal circuit of the semiconductor light-emitting device, and the problem of uneven light brightness at the head and tail of the LED light strip can be improved by applying it to the LED light strip, and compared with directly connecting a single LED chip and a CRD chip in series, the semiconductor light-emitting device of this embodiment can greatly reduce the overall volume of the device; the number of LED epitaxial structures is greater than the number of CRD epitaxial structures, so that one CRD can constant the current of multiple LEDs, ensuring the efficient use of the CRD epitaxial structure. And the production difficulty can be reduced while meeting the performance of appropriate current constant and uniform brightness.
[0014] Other aspects and features of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. It should be understood, however, that the drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. It should also be understood that, unless otherwise indicated, the drawings are not necessarily drawn to scale and are intended only to conceptually illustrate the structures and processes described herein. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The specific implementation modes of the present invention will be described in detail below with reference to the accompanying drawings.
[0016] Figure 1A schematic diagram of the side structure of a semiconductor light emitting device provided in an embodiment of the present invention.
[0017] Figure 2 A schematic diagram of the side structure of a semiconductor light emitting device provided in another embodiment of the present invention.
[0018] Figure 3 A schematic diagram of the arrangement relationship between a CRD epitaxial structure and an LED epitaxial structure in a semiconductor light-emitting device provided by an embodiment of the present invention.
[0019] Figure 4 A schematic diagram of the arrangement relationship between a CRD epitaxial structure and an LED epitaxial structure in a semiconductor light emitting device provided in another embodiment of the present invention.
[0020] Figure 5 A schematic diagram of the arrangement relationship between a CRD epitaxial structure and an LED epitaxial structure in a semiconductor light emitting device provided in yet another embodiment of the present invention.
[0021] Figure 6 for Figure 1 A schematic diagram of the structure obtained in a step in a preparation process of a semiconductor light-emitting device is shown.
[0022] Figure 7 for Figure 6 Schematic representation of the resulting structure one step later.
[0023] Figure 8 for Figure 7 A schematic diagram of the structure obtained in the next step.
[0024] Fig. 9 for Figure 8 A schematic diagram of the structure obtained in the next step.
[0025] Fig.10 for Fig. 9 A schematic diagram of the structure obtained in the next step.
[0026] [Description of Reference Numerals]
[0027] 10. CRD epitaxial structure; 10a. CRD epitaxial structure material layer; 11. CRD epitaxial layer; 111. Channel layer; 112. Isolation layer; 113. Barrier layer; 12. First high resistance buffer layer; 13. First buffer layer; 131. First AlN layer; 132. Second AlN layer; 133. First low temperature growth GaN layer. 20. LED epitaxial structure; 20a. LED epitaxial structure material layer; 21. LED epitaxial layer; 211. N-type semiconductor layer; 212. N-type isolation layer; 213. Stress adjustment layer; 214. Quantum well layer; 215. Electron blocking layer; 216. P-type semiconductor layer; 22. Second high resistance buffer layer; 23. Second buffer layer; 231. Third AlN layer; 232. Fourth AlN layer; 233. Second low temperature growth GaN layer; 30. Substrate; 40. Growth inhibition layer. DETAILED DESCRIPTION
[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.
[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0031] It should also be noted that the division of multiple embodiments in the present invention is only for the convenience of description and should not constitute a special limitation. The features in various embodiments can be combined and referenced to each other without contradiction.
[0032] like Figure 1As shown, a semiconductor light-emitting device provided by an embodiment of the present invention includes a substrate 30, an LED epitaxial structure 20 and a CRD (Current Regulative Diode) epitaxial structure 10. Among them, the LED epitaxial structure 20 includes an LED epitaxial layer 21, and the LED epitaxial layer 21 specifically includes an N-type semiconductor layer 211, a quantum well layer 214 and a P-type semiconductor layer 216 sequentially arranged on the substrate. The CRD epitaxial structure 10 is arranged on the side of the substrate 30 facing the LED epitaxial structure 20 and is spaced from the LED epitaxial structure 20. The CRD epitaxial structure 10 includes a CRD epitaxial layer 11, and the CRD epitaxial layer 11 includes a channel layer 111 and a barrier layer 113 sequentially arranged on the substrate 30.
[0033] The substrate 30 is, for example, an Al2O3 (sapphire) substrate.
[0034] The N-type semiconductor layer 211 in the LED epitaxial structure 20 is an N-type silicon-doped GaN (gallium nitride) layer, and the thickness of the N-type semiconductor layer 211 is, for example, 1 to 4 μm. The silicon concentration in the N-type semiconductor layer 211 is in the range of 1*10 19 cm -3 ~3*10 19 cm -3 The quantum well layer 214 is, for example, a superlattice multiple quantum well light-emitting layer. The P-type semiconductor layer 216 is a P-type magnesium-doped GaN layer. In some embodiments, the LED epitaxial layer 21 may further include an N-type isolation layer 212 located on the side of the N-type semiconductor layer 211 away from the substrate 30. The N-type isolation layer 212 may be a silicon-doped GaN layer. The silicon concentration in the N-type isolation layer 212 is in the range of 1*10 17 cm -3 ~8*10 18 cm -3 In some embodiments, a stress adjustment layer 213 is further provided between the N-type isolation layer 212 (or the N-type semiconductor layer 211) and the quantum well layer 214. The stress adjustment layer 213 is, for example, an InGaN / GaN superlattice layer, and the concentration of In (indium) in the stress adjustment layer 213 is lower than the concentration of In in the quantum well layer 214. In some embodiments, an electron blocking layer 215 is further provided between the quantum well layer 214 and the P-type semiconductor layer 216. The electron blocking layer 215 is, for example, an AlGaN (aluminum gallium nitrogen) layer, and the thickness is, for example, 10 to 30 nm (nanometers).
[0035] In the CRD epitaxial structure 10, the channel layer 111 is specifically a GaN layer, and the thickness is, for example, 100 to 300 nm. The barrier layer 113 is specifically an AlGaN layer, and the thickness is, for example, 10 to 30 nm, and the content of the Al component is 20% to 30%. In some embodiments, there is an isolation layer 112 between the channel layer 111 and the barrier layer 113, and the isolation layer 112 is specifically an AlN (aluminum nitride) layer, and the thickness is, for example, 1 to 2 nm.
[0036] In some embodiments, the CRD epitaxial structure 10 further includes a buffer layer between the CRD epitaxial layer 11 and the substrate 30, specifically including a first buffer layer 13 and a first high resistance buffer layer 12 sequentially disposed on the substrate, wherein the first buffer layer 13 contains AlN, and the first high resistance buffer layer 12 contains GaN.
[0037] For example, the first buffer layer 13 includes one or more layers of AlN, and the first buffer layer 13 may also be referred to as an AlN layer. In some embodiments, the first buffer layer 13 includes a first AlN layer 131 and a second AlN layer 132, the first AlN layer 131 has a thickness of 10 to 100 nm, and the second AlN layer 132 has a thickness of 1 to 100 nm. In some embodiments, the first buffer layer 13 also includes a first low-temperature grown GaN layer 133 located on the second AlN layer 132, and the first low-temperature grown GaN layer is a non-doped GaN layer.
[0038] The first high resistance buffer layer 12 can achieve a higher resistance by, for example, doping with Fe or C sources. In some embodiments, the first high resistance buffer layer 12 can also be an undoped GaN layer, and the thickness of the first high resistance buffer layer 12 ranges from 1 to 3 microns. Since the first low-temperature grown GaN layer 133 and the first high resistance buffer layer 12 are both GaN materials, the combination of the first low-temperature grown GaN layer 133 and the first high resistance buffer layer 12 can also be referred to as the first GaN buffer layer located between the channel layer 111 and the substrate 30. The stacked structure of the first buffer layer 13 and the first high resistance buffer layer 12 can also be regarded as a stack of AlN layer and the first GaN buffer layer. Among them, the first AlN layer 131 and the second AlN layer 132 in the first buffer layer 13 can improve the crystal quality of the subsequently grown GaN material, and the setting of the first low-temperature grown GaN layer 133 is conducive to stress release, which can effectively avoid cracks in the appearance of the CRD epitaxial structure 10.
[0039] In the semiconductor light-emitting device provided by the embodiment of the present invention, the LED epitaxial structure 20 can form an LED chip in the subsequent preparation process, so that it has the characteristics of LED light emission when powered on, and the CRD epitaxial structure 10 can form a CRD chip in the subsequent preparation process. When powered on, it has the characteristics of constant current and high voltage resistance of a constant current diode, so that the semiconductor light-emitting device is equivalent to integrating the functions of an LED chip and a CRD chip in one. The LED epitaxial structure 20 and the CRD epitaxial structure 10 can be connected in series through the internal circuit of the semiconductor light-emitting device. Applying the semiconductor light-emitting device provided by this embodiment to the LED light strip can improve the problem of uneven light brightness at the head and tail of the LED light strip, and compared with directly connecting a single LED chip and a CRD chip in series, the semiconductor light-emitting device of this embodiment can greatly reduce the overall volume of the device.
[0040] Among them, the number of LED epitaxial structures 20 is multiple, and the number of LED epitaxial structures 20 is greater than the number of CRD epitaxial structures, that is, the ratio of the number of LED epitaxial structures 20 to the number of CRD epitaxial structures 10 on the same substrate 30 is N:1, where N>1, and the multiple LED epitaxial structures 20 are spaced apart from the CRD epitaxial structure 10, and the multiple LED epitaxial structures 20 are spaced apart from each other.
[0041] In this embodiment, the LED epitaxial structure 20 and the CRD epitaxial structure 10 are arranged in an N:1 manner on the same substrate 30, and a CRD chip can be used on the same chip product to provide constant current for multiple LED chips, ensuring that the current of the LED is uniform and the luminous brightness is more uniform, so that the CRD of the corresponding size is fully utilized, and the production difficulty of the product can be reduced, and the usual CRD design specifications can be applied. In the subsequent preparation process, electrodes can be prepared through a metal layer on multiple LED epitaxial structures 20 and CRD epitaxial structures 10 and multiple epitaxial structures can be connected in series. Compared with multiple independent chips, the wiring connection is less difficult and the connection is more stable. In addition, due to the constant current function of the integrated CRD chip, multiple LED chips made of multiple LED epitaxial structures 20 can emit light more uniformly, so the original larger LED chip can be converted into multiple smaller LED chips. Compared with the same brightness requirement, the production difficulty is reduced, and the obtained integrated chip is more suitable for outdoor scenes with higher brightness requirements.
[0042] Reference Figure 3 , which shows an arrangement of multiple LED epitaxial structures 20 arranged in sequence and at intervals on one side of the CRD epitaxial structure 10.
[0043] Reference Figure 4, which shows that a plurality of LED epitaxial structures 20 are arranged in an array along the adjacent two sides of the CRD epitaxial structure 10. Specifically, in the semiconductor light-emitting device, a plurality of epitaxial structures (including the LED epitaxial structure 20 and the CRD epitaxial structure 10) are arranged in a rectangular array of multiple rows and columns, wherein the CRD epitaxial structure 10 is located at a vertex of the rectangular array.
[0044] Reference Figure 5 , which shows a structure in which multiple LED epitaxial structures 20 are arranged around a CRD epitaxial structure 10. Specifically, in the semiconductor light-emitting device, multiple epitaxial structures (including LED epitaxial structures 20 and CRD epitaxial structures 10) are arranged in a rectangular array of multiple rows and columns, wherein the CRD epitaxial structure 10 is located in the middle of the rectangular array.
[0045] It should be noted that Figures 4 to 5 The number of LED epitaxial structures 20 is only for illustration, and the embodiments of the present invention are not limited to the above examples.
[0046] In some embodiments, the orthographic projection patterns of the multiple LED epitaxial structures 20 on the substrate 30 are of the same size, which can make the current in the semiconductor light-emitting device more uniform and the light effect more uniform. For example, the orthographic projection patterns of the multiple LED epitaxial structures 20 on the substrate 30 are multiple rectangles, and the length and width of each rectangle are equal. For example, the orthographic projection patterns of each LED epitaxial structure 20 on the substrate are all 7mil*15mil (1mil=0.001 inch) rectangles.
[0047] In some embodiments, the gap between two adjacent LED epitaxial structures 20 is less than or equal to the gap between the LED epitaxial structure 20 and the CRD epitaxial structure 10. Figure 5 The gap width between the two adjacent LED epitaxial structures 20 is W2, and the gap between the CRD epitaxial structure 10 and the LED epitaxial structure adjacent to its left is W1, that is, W2 is less than or equal to W1. Among them, the gap width W1 between the CRD epitaxial structure 10 and the LED epitaxial structure 20 is greater than or equal to 60 microns, which can ensure the relative independence between the CRD epitaxial structure 10 and the LED epitaxial structure 20.
[0048] In some embodiments, reference Figures 4 to 5, the area of the orthographic projection pattern of the CRD epitaxial structure 10 on the substrate 30 is smaller than the area of the orthographic projection pattern of a single LED epitaxial structure 20 on the substrate 30. For example, the orthographic projection pattern of the CRD epitaxial structure 10 on the substrate 30 is a rectangle of 8mil*10mil. The CRD chip including the CRD epitaxial structure 10 has a constant current function. Setting the CRD epitaxial structure 10 smaller can reduce product costs, and setting the size of the LED epitaxial structure 20 larger can ensure the luminous brightness of the LED chip.
[0049] In some embodiments, Figure 1 The LED epitaxial structure 20 shown includes a second high resistance buffer layer 22 located between the N-type semiconductor layer 211 and the substrate 30. The second high resistance buffer layer 22 is, for example, a non-doped GaN layer, which can be the same or different from the material of the first high resistance buffer layer 12. For example, in some embodiments, the first high resistance buffer layer 12 is a GaN layer doped with Fe or C, and the second high resistance buffer layer 22 is a non-doped GaN layer. Alternatively, in some embodiments, both the first high resistance buffer layer 12 and the second high resistance buffer layer 22 are non-doped GaN layers. The thickness of the second high resistance buffer layer 22 is, for example, 2 to 4 microns.
[0050] The LED epitaxial structure 20 also includes a second buffer layer 23 between the second high resistance buffer layer 22 and the substrate 30. In some embodiments, the second buffer layer 23 includes a second low temperature grown GaN layer 233. The second low temperature grown GaN layer 233 is conducive to the release of stress and can prevent cracks from appearing on the appearance of the LED epitaxial structure 20. The second low temperature grown GaN layer 233 is a non-doped GaN layer. The combination of the second low temperature grown GaN layer 233 and the second high resistance buffer layer 22 can be called a second GaN buffer layer. That is, the LED epitaxial structure 20 includes a second GaN buffer layer between the N-type semiconductor layer 211 and the substrate 30. In some embodiments, the thickness of the second GaN buffer layer is greater than the thickness of the first GaN buffer layer in the CRD epitaxial structure 10. That is, the sum of the thickness of the second low temperature grown GaN layer 233 and the second high resistance buffer layer 22 is greater than the sum of the thickness of the first low temperature grown GaN layer 133 and the first high resistance buffer layer 12. In some specific embodiments, the ratio of the total thickness of the LED epitaxial structure 20 to the total thickness of the CRD epitaxial structure 10 is in the range of 1.7 to 3.5. The CRD epitaxial structure 10 is thinner, which reduces the chip process breakage rate to a certain extent and improves the yield. It can avoid the problem that the CRD epitaxial 10 is too thick, resulting in a large warping and then uneven distribution of the Al component in the AlGaN barrier layer. The thicker thickness of the LED epitaxial structure 20 can ensure the quality requirements of the GaN crystal. For example, the total thickness of the CRD epitaxial structure 10 ranges from 2 to 3 microns, and the total thickness of the LED epitaxial structure 20 ranges from 5 to 7 microns.
[0051] Reference Figure 2 In some embodiments, the second buffer layer 23, for example, further includes a third AlN layer 231 and a fourth AlN layer 232 located between the second low-temperature grown GaN layer 233 and the substrate 30 and sequentially stacked on the substrate 30. The thickness of the third AlN layer 231 may be the same as the thickness of the first AlN layer 131, and the thickness of the fourth AlN layer 232 may be the same as the thickness of the second AlN layer 231.
[0052] The method for preparing the semiconductor light-emitting device provided in the above embodiment of the present invention comprises:
[0053] S1: growing a first epitaxial structure material layer on a substrate;
[0054] S2: forming a growth inhibition layer on a side of the first epitaxial structure material layer away from the substrate;
[0055] S3: etching a portion of the first epitaxial structure material layer to obtain a first epitaxial structure disposed on a partial region of the substrate;
[0056] S4: growing a second epitaxial structure material layer on the substrate in an area exposed outside the first epitaxial structure;
[0057] S5: etching the junction between the second epitaxial structure material layer and the first epitaxial structure layer to obtain a first epitaxial structure and a second epitaxial structure spaced apart from each other;
[0058] One of the first epitaxial structure and the second epitaxial structure is an LED epitaxial structure 20, and the other is a CRD epitaxial structure 10. The specific hierarchical structures of the LED epitaxial structure 20 and the CRD epitaxial structure 10 can refer to the description of the above embodiments.
[0059] in, Figures 6 to 10The schematic diagram of the structure obtained after each step of the preparation method in which the first epitaxial structure layer is a CRD epitaxial structure 10 and the second epitaxial structure layer is an LED epitaxial structure 20. In step S1, the materials corresponding to the required layers of the CRD epitaxial structure 10 are sequentially grown on the substrate 30. Specifically, for example, S11: forming a first AlN material layer on the substrate 30 by PECVD (subsequently corresponding to forming a first AlN layer 131); S12: performing heat treatment in a high temperature (1000-1200°C) hydrogen environment for 8-12 minutes; S13: growing a second AlN material layer on the first AlN layer 131 by MOCVD (subsequently corresponding to forming a second AlN layer 132); S14: low temperature growth of a GaN layer (subsequently corresponding to forming a first low temperature growth GaN layer 133); that is, the various layers of materials required for growing the first buffer layer 13 in steps S11 to S14. After step S14, step S15 is performed: a high-resistance GaN layer is grown under a high temperature condition of 1000-1150°C (the first high-resistance buffer layer 12 is formed correspondingly later); after step S15, step S16 is performed: the materials required for each layer corresponding to the CRD epitaxial layer 11 are sequentially formed, for example, a GaN layer, an AlN layer and an AlGaN material layer are sequentially formed, so as to sequentially form a channel layer 111, an isolation layer 112 and a barrier layer 113 in the subsequent process. After step S1 is completed, step S16 is performed. Figure 6 The substrate 30 shown has a CRD epitaxial structure material layer 10 a formed thereon.
[0060] The structure obtained after step S2 is completed can be referred to Figure 7 As shown, the growth inhibition layer 40 may be made of a material that inhibits growth, such as native SiN (silicon nitride) material. When the growth inhibition layer 40 is made of native SiN material, the barrier layer 113 may be directly protected from leakage.
[0061] In step S3, the area on the substrate 30 where the CRD epitaxial structure 10 is subsequently formed can be referred to as a preset area. In step S3, the portion of the CRD epitaxial structure material layer 10a located outside the preset area can be completely or partially removed, and the portion of the CRD epitaxial structure material layer 10a within the preset area is not etched to form a CRD epitaxial structure. Here, "complete removal" means that the surface of the substrate 30 located outside the preset area is exposed, and the first AlN material layer formed in step S11 and the material layer thereon are etched away. That is, in some embodiments, step S3 specifically includes step S31: etching all material layers of the first epitaxial structure material layer outside the preset area, so that the first epitaxial structure is formed in the preset area, and the surface of the substrate located outside the preset area is exposed. Figure 8 The structure obtained after step S31 is completed is shown.
[0062] In other embodiments, in step S3, the portion of the CRD epitaxial structure material layer 10a outside the preset region is partially removed, for example, the surface of the high-resistance GaN layer formed in step S14 is etched to be exposed, and the region above the high-resistance GaN layer is etched away. That is, in some embodiments, step S3 specifically includes step S32: etching the portion of the material layer of the first epitaxial structure material layer outside the preset region, so that the first epitaxial structure is formed in the preset region, and the surface of the substrate outside the preset region is covered by the portion of the material layer of the first epitaxial structure material layer.
[0063] Compared with step S32, step S31 can avoid the problem of poor flatness of the GaN material layer caused by etching, so that the material layer grown in the subsequent step S4 can be directly grown on the surface of the substrate 30 with better growth quality.
[0064] In step S4, if step S31 is used in the aforementioned step S3, then step S4 specifically includes, for example, step S41: low-temperature growth of a GaN buffer layer on the structure obtained in step S3 (subsequently corresponding to the formation of a second low-temperature grown GaN layer 233); step S42: growth of an undoped GaN layer at a temperature of 1000 to 1150°C (subsequently corresponding to the formation of a second high-resistance buffer layer 22); through steps S41 and S42, the various layers of materials required for the second buffer layer 23 and the second high-resistance buffer layer 22 can be grown. After step S42 is completed, the various layers of materials required to form the LED epitaxial layer are grown, for example, including steps S43 to S47. Step S43: Growth of an N-type silicon-doped GaN layer (subsequently corresponding to the formation of an N-type semiconductor layer 211), with a silicon concentration range of 1*10 19 cm -3 ~3*10 19 cm -3 (The N-type semiconductor layer 211 is formed accordingly later); Step S44: growing a silicon-doped GaN layer, with a silicon concentration range of 1*10 17 cm -3 ~8*10 18 cm -3 (Subsequently, an N-type isolation layer 212 is formed correspondingly); Step S45: growing an InGaN / GaN superlattice layer (subsequently, a stress adjustment layer 213 is formed correspondingly), with a barrier silicon doping concentration range of 1*17cm -3 ~8*18cm -3, temperature range 750~950℃; Step S46: Use high purity N2 as the main carrier gas, TMGa, TEGa, TMAl, TMIn and NH3 as Ga source, Al source, In source and N source. Grow a superlattice multiple quantum well light-emitting layer (subsequently corresponding to form a quantum well layer 214). Step S47: Grow an AlGaN layer (subsequently corresponding to form an electron blocking layer 215). Step S48: Dope magnesium to grow a P-type GaN layer (subsequently corresponding to form a P-type semiconductor layer 216). In step S4, since the top of the CRD epitaxial structure 10 is covered with a growth inhibition layer 40, the aforementioned layers of materials will only grow in the portion outside the preset area. The structure obtained after step S4 can refer to Fig. 9 As shown, at this time, the CRD epitaxial structure 10 and the LED epitaxial structure material layer 20 a are adjacent to and in contact with each other.
[0065] If step S32 is used in step S3, step S41 may be omitted, and step S42 and subsequent steps may be directly performed. That is, in the semiconductor light-emitting device finally prepared, the first low-temperature grown GaN133 layer and the second low-temperature grown GaN233 material layer are both formed in step S14.
[0066] When the third AlN layer 231 and the fourth AlN layer 232 are provided in the LED epitaxial structure 20, if step S32 is adopted in step S3, the material layers of the third AlN layer 231 and the first AlN layer 131 are both formed in step S11. The fourth AlN layer 232 and the second AlN layer 132 are both formed in step S13. If step S31 is adopted in step S3, the material layers for forming the third AlN layer 231 and the fourth AlN layer 232 can be prepared before step S41 with reference to the process conditions in steps S11 to S13.
[0067] In each sub-step of step S4 , when the reaction temperature is higher than 500° C., sufficient NH 3 (ammonia) needs to be introduced to provide nitrogen atoms to protect the CRD epitaxial structure 10 .
[0068] In step S5, ICP etching can be used to etch the junction between the CRD epitaxial structure 10 and the LED epitaxial structure material layer 20a to obtain the CRD epitaxial structure 10 and the LED epitaxial structure 20 spaced apart from each other, and ISO is plated at the spaced apart locations for protection. The structure diagram obtained after step S5 is completed can be referred to Fig.10 Subsequently, the growth inhibition layer 40 may be retained or removed according to actual needs.
[0069] In other embodiments, the first epitaxial structure layer is an LED epitaxial structure 20 and the second epitaxial structure layer is a CRD epitaxial structure 10. In step S1, the material corresponding to the required layer of the LED epitaxial structure 20 is first grown on one side of the substrate 30 to obtain the LED epitaxial structure material layer 20a. The specific process steps and conditions can refer to the contents of the above steps S41 to S47, which will not be repeated here. The area on the substrate 30 corresponding to the CRD epitaxial structure 10 is a preset area. In step S3, part or all of the LED epitaxial structure material layer 20a located in the preset area is removed to obtain the LED epitaxial structure 20. In step S4, the various material layers required to form the CRD epitaxial structure 10 are grown in the preset area to obtain the CRD epitaxial structure material layer 10a. The specific process steps and conditions can refer to the contents of the above steps S11 to S16, which will not be repeated here. Compared with the embodiment in which the first epitaxial structure layer is the LED epitaxial structure 20 and the second epitaxial structure layer is the CRD epitaxial structure 10, the first epitaxial structure layer is the CRD epitaxial structure 10 and the second epitaxial structure layer is the LED epitaxial structure 20 can avoid the problem of high temperature affecting the InGaN layer in the quantum well layer 214 of the LED epitaxial structure 20 during the preparation of the CRD epitaxial structure material layer 10a, thereby causing the LED light efficiency to deteriorate.
[0070] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A semiconductor light emitting device, characterized in that: include: substrate; The LED epitaxial structure comprises an N-type semiconductor layer, a quantum well layer and a P-type semiconductor layer sequentially arranged on the substrate; the number of the LED epitaxial structures is multiple, and the multiple LED epitaxial structures are arranged at intervals from each other; The CRD epitaxial structure is arranged on a side of the substrate facing the LED epitaxial structure and is spaced apart from the LED epitaxial structure. The CRD epitaxial structure includes a first buffer layer, a first high-resistance buffer layer, a channel layer, an isolation layer and a barrier layer which are sequentially arranged on the substrate. The first buffer layer contains AlN, and the first high-resistance buffer layer contains GaN. The number of the LED epitaxial structures is greater than the number of the CRD epitaxial structures.
2. The semiconductor light emitting device according to claim 1, characterized in that: A plurality of LED epitaxial structures are sequentially arranged at intervals on one side of the CRD epitaxial structure; or, A plurality of LED epitaxial structures are arranged around the CRD epitaxial structure; or, The plurality of LED epitaxial structures are arranged in an array along two adjacent sides of the CRD epitaxial structure.
3. The semiconductor light emitting device according to claim 2, characterized in that: The orthographic projection patterns of the plurality of LED epitaxial structures on the substrate have the same size; and / or, The gap between two adjacent LED epitaxial structures is smaller than or equal to the gap between the LED epitaxial structure and the CRD epitaxial structure; and / or, The area of the orthographic projection pattern of the CRD epitaxial structure on the substrate is smaller than the area of the orthographic projection pattern of a single LED epitaxial structure on the substrate.
4. The semiconductor light emitting device according to claim 1, characterized in that: The gap width between the CRD epitaxial structure and the LED epitaxial structure is greater than or equal to 60 micrometers.
5. The semiconductor light emitting device according to claim 1, characterized in that: The first buffer layer includes a first low-temperature grown GaN layer, the first high-resistance buffer layer is a high-resistance GaN layer, the LED epitaxial structure includes a second GaN buffer layer located between the N-type semiconductor layer and the substrate, and the thickness of the second GaN buffer layer is greater than the sum of the thicknesses of the low-temperature grown GaN layer and the first high-resistance buffer layer.
6. The semiconductor light emitting device according to claim 5, characterized in that: The high-resistance GaN layer and the second GaN buffer layer are both undoped GaN layers.
7. A method for preparing a semiconductor light-emitting device, characterized in that: include: S1: growing a first epitaxial structure material layer on a substrate; S2: forming a growth inhibition layer on a side of the first epitaxial structure material layer away from the substrate; S3: etching a portion of the first epitaxial structure material layer to obtain a first epitaxial structure disposed on a partial region of the substrate; S4: growing a second epitaxial structure material layer on the substrate in an area exposed outside the first epitaxial structure; S5: etching the junction between the second epitaxial structure material layer and the first epitaxial structure to obtain a first epitaxial structure and a second epitaxial structure spaced apart from each other; One of the first epitaxial structure and the second epitaxial structure is an LED epitaxial structure, comprising an N-type semiconductor layer, a quantum well layer and a P-type semiconductor layer sequentially arranged on the substrate; the other is a CRD epitaxial structure, comprising a first buffer layer, a first high-resistance buffer layer, a channel layer, an isolation layer and a barrier layer sequentially arranged on the substrate; the first buffer layer contains AlN, and the first high-resistance buffer layer contains GaN; There are multiple LED epitaxial structures, and the multiple LED epitaxial structures are arranged at intervals from each other; and the number of the LED epitaxial structures is greater than the number of the CRD epitaxial structures.
8. The method for preparing a semiconductor light emitting device according to claim 7, characterized in that: The first epitaxial structure layer is a CRD epitaxial structure; the second epitaxial layer is an LED epitaxial structure.
9. The method for preparing a semiconductor light emitting device according to claim 7, characterized in that: The growth inhibition layer is a SiN layer.
10. The method for preparing a semiconductor light emitting device according to claim 7, characterized in that: The S3 specifically includes: etching all material layers of the first epitaxial structure material layer outside a preset area to form a first epitaxial structure in the preset area and expose the surface of the substrate outside the preset area.