CN115172542A - LED epitaxial wafer, epitaxial growth method and LED chip - Google Patents

Abstract

The invention provides aN LED epitaxial wafer, aN epitaxial growth method and aN LED chip, wherein the LED epitaxial wafer comprises a non-doped GaN layer, the non-doped GaN layer is a B-doped BaGa1-aN material, a is 0.005-Ap-0.1, wherein the B component of the non-doped GaN layer is gradually increased from one end of the non-doped GaN layer to the other opposite end, and due to the fact that the B component is doped into the non-doped GaN layer and the radius of the B atom is smaller, lattice defects in the GaN growth process can be filled, and the crystal quality of GaN is improved. In addition, when the GaN crystal is just grown, the quality is poor, the number of defects is large, as the concentration of the B component is gradually increased, B atoms can fill the defects generated by the crystal growth, and as the thickness of the crystal is increased, the compressive stress can be released through stacking faults, the line defects are reduced, and the quality of the crystal is higher.

Description

Translated fromChinese

一种LED外延片、外延生长方法及LED芯片A kind of LED epitaxial wafer, epitaxial growth method and LED chip

技术领域technical field

本发明涉及LED技术领域，特别涉及一种LED外延片、外延生长方法及LED芯片。The invention relates to the technical field of LEDs, in particular to an LED epitaxial wafer, an epitaxial growth method and an LED chip.

背景技术Background technique

发光二极管(Light Emitting Diode，简称：LED)是一种能发光的半导体电子元件，由于其体积小、亮度高、能耗低等特点，吸引了越来越多研究者的注意。Light Emitting Diode (LED) is a semiconductor electronic component that can emit light. Due to its small size, high brightness, and low energy consumption, it has attracted more and more researchers' attention.

其中，GaN基LED器件具有绿色环保、能耗低、抗腐蚀，发光效率高等特点，广泛的应用在照明、手机/电脑显示屏背光源等行业，而GaN基LED器件制造的好坏与LED外延的生长情况息息相关。Among them, GaN-based LED devices have the characteristics of green environmental protection, low energy consumption, corrosion resistance, and high luminous efficiency, and are widely used in lighting, mobile phone/computer display backlight and other industries. The quality of GaN-based LED device manufacturing is closely related to LED epitaxy. growth is closely related.

传统的LED外延是以蓝宝石为衬底、以及依次层叠在蓝宝石衬底上的缓冲层、非掺杂GaN层、N型GaN层、有源层、P型层，因蓝宝石与GaN的晶格适配较大，所制备得到的外延片存在点缺陷、线缺陷、位错等缺陷，导致晶体质量较差，所制备LED芯片的光电性能不佳。目前改善LED外延片晶体质量的主要方式是在非掺杂GaN层或N型GaN层后沉积一层高Al组分AlGaN缺陷阻挡层来阻挡位错向外延片生长方向扩张，但是该方式中的Al原子迁移率较低，且与NH3副反应较多，因此，想要出较高晶体质量的高Al组分的AlGaN缺陷阻挡层及其困难。The traditional LED epitaxy is based on sapphire substrate, and the buffer layer, undoped GaN layer, N-type GaN layer, active layer, and P-type layer are sequentially stacked on the sapphire substrate. If the configuration is large, the prepared epitaxial wafer has defects such as point defects, line defects, and dislocations, resulting in poor crystal quality and poor optoelectronic properties of the prepared LED chips. At present, the main way to improve the crystal quality of LED epitaxial wafers is to deposit a high Al composition AlGaN defect barrier layer after the undoped GaN layer or N-type GaN layer to prevent dislocations from expanding in the epitaxial wafer growth direction. The mobility of Al atoms is low, and the side reactions with NH3 are more. Therefore, it is difficult to obtain AlGaN defect barrier layers with high Al composition and high crystal quality.

发明内容SUMMARY OF THE INVENTION

基于此，本发明的目的是提供一种LED外延片、外延生长方法及LED芯片，旨在解决现有蓝宝石与GaN的晶格适配较大，导致晶体质量较差的问题。Based on this, the purpose of the present invention is to provide an LED epitaxial wafer, an epitaxial growth method and an LED chip, which aims to solve the problem that the existing sapphire and GaN have a large lattice adaptation, resulting in poor crystal quality.

根据本发明实施例当中的一种LED外延片，包括非掺杂GaN层，所述非掺杂GaN层为掺杂B的BaGa1-aN材料，a为0.005<a<0.1，其中，所述非掺杂GaN层的B组分从所述非掺杂GaN层的一端向相对的另一端逐渐增加。An LED epitaxial wafer according to an embodiment of the present invention includes an undoped GaN layer, the undoped GaN layer is a B-doped BaGa1-aN material, and a is 0.005<a<0.1, wherein the non-doped GaN layer is a B-doped BaGa1-aN material. The B component of the doped GaN layer gradually increases from one end of the undoped GaN layer to the opposite end.

优选地，所述LED外延片还包括蓝宝石衬底、缓冲层、n型GaN层、多量子阱层、电子阻挡层，P型GaN层；Preferably, the LED epitaxial wafer further comprises a sapphire substrate, a buffer layer, an n-type GaN layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer;

所述缓冲层、所述非掺杂GaN层、所述n型GaN层、所述多量子阱层、所述电子阻挡层，所述P型GaN层依次外延生长在所述蓝宝石衬底上。The buffer layer, the undoped GaN layer, the n-type GaN layer, the multiple quantum well layer, the electron blocking layer, and the P-type GaN layer are epitaxially grown on the sapphire substrate in sequence.

优选地，所述缓冲层的厚度为10nm～30nm，所述非掺杂GaN层的厚度为1um～5um、所述n型GaN层的厚度为2um～3um、所述多量子阱层的厚度为11nm～15.5nm、所述电子阻挡层的厚度为10nm～40nm，所述P型GaN层的厚度为10nm～50nm。Preferably, the thickness of the buffer layer is 10 nm to 30 nm, the thickness of the undoped GaN layer is 1 μm to 5 μm, the thickness of the n-type GaN layer is 2 μm to 3 μm, and the thickness of the multiple quantum well layer is 11 nm to 15.5 nm, the thickness of the electron blocking layer is 10 nm to 40 nm, and the thickness of the P-type GaN layer is 10 nm to 50 nm.

优选地，所述多量子阱层为AlGaN层和InGaN层交替生长而成的周期性结构。Preferably, the multiple quantum well layer is a periodic structure formed by alternately growing AlGaN layers and InGaN layers.

根据本发明实施例当中的一种LED外延片的外延生长方法，用于制备上述的LED外延片，所述外延生长方法包括：An epitaxial growth method for an LED epitaxial wafer according to an embodiment of the present invention is used to prepare the above-mentioned LED epitaxial wafer, and the epitaxial growth method includes:

在生长非掺杂GaN层时，控制B组分和N2/H2/NH3的混合气体通入，其中，非掺杂GaN层为掺杂B的BaGa1-aN材料，a为0.005<a<0.1。When growing the undoped GaN layer, control the introduction of the B component and the mixed gas of N2/H2/NH3, wherein the undoped GaN layer is a B-doped BaGa1-aN material, and a is 0.005<a<0.1.

优选地，所述外延生长方法还包括：Preferably, the epitaxial growth method further comprises:

提供一生长所需的蓝宝石衬底；providing a sapphire substrate required for growth;

在所述蓝宝石衬底上依次外延生长缓冲层、非掺杂GaN层、n型GaN层、多量子阱层、电子阻挡层和P型GaN层。A buffer layer, an undoped GaN layer, an n-type GaN layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer are sequentially epitaxially grown on the sapphire substrate.

优选地，所述在生长非掺杂GaN层时，控制B组分和N2/H2/NH3的混合气体通入的步骤包括：Preferably, when the undoped GaN layer is grown, the step of controlling the introduction of the mixed gas of the B component and N2/H2/NH3 includes:

控制B组分的通入流量由第一流量逐渐减小至第二流量，且控制N2/H2/NH3的混合气体中NH3的通入流量由第三流量逐渐减小至第四流量，生长得到所述非掺杂GaN层。Control the incoming flow rate of component B to gradually decrease from the first flow rate to the second flow rate, and control the incoming flow rate of NH3 in the mixed gas of N2/H2/NH3 from the third flow rate to the fourth flow rate gradually. the undoped GaN layer.

优选地，所述非掺杂GaN层的生长压力为100torr～600torr，所述非掺杂GaN层的生长温度为1000℃～1200℃。Preferably, the growth pressure of the undoped GaN layer is 100torr˜600torr, and the growth temperature of the undoped GaN layer is 1000°C˜1200°C.

根据本发明实施例当中的一种LED芯片，包括上述的LED外延片。An LED chip according to an embodiment of the present invention includes the above-mentioned LED epitaxial wafer.

与现有技术相比：GaN在生长过程会出现点缺陷、线缺陷等缺陷，本发明由于在非掺杂GaN层中掺入B组分，而B原子半径较小，可以填充GaN生长过程中晶格缺陷，改善GaN的晶体质量。此外，GaN刚开始生长晶体时，质量较差，缺陷较多，随着B组分浓度逐渐升高，B原子将会填充长晶产生的缺陷，且随着晶体厚度的增加，压应力会通过堆垛层错释放，线缺陷减少，晶体质量越高。Compared with the prior art: GaN will have defects such as point defects and line defects during the growth process. In the present invention, since the B component is doped into the undoped GaN layer, and the B atomic radius is small, it can fill the GaN growth process. Lattice defects, improving the crystal quality of GaN. In addition, when GaN crystal grows, the quality is poor and there are many defects. As the concentration of B component gradually increases, B atoms will fill the defects generated by the crystal growth, and as the thickness of the crystal increases, the compressive stress will pass through The stacking fault is released, the line defects are reduced, and the crystal quality is higher.

附图说明Description of drawings

图1为本发明实施例一当中的LED外延片的结构示意图；1 is a schematic structural diagram of an LED epitaxial wafer in Embodiment 1 of the present invention;

图2为本发明实施例二当中的LED外延片的外延生长方法的流程图。FIG. 2 is a flowchart of an epitaxial growth method of an LED epitaxial wafer in Embodiment 2 of the present invention.

具体实施方式Detailed ways

为了便于理解本发明，下面将参照相关附图对本发明进行更全面的描述。附图中给出了本发明的若干实施例。但是，本发明可以以许多不同的形式来实现，并不限于本文所描述的实施例。相反地，提供这些实施例的目的是使对本发明的公开内容更加透彻全面。In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the related drawings. Several embodiments of the invention are shown in the drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

需要说明的是，当元件被称为“固设于”另一个元件，它可以直接在另一个元件上或者也可以存在居中的元件。当一个元件被认为是“连接”另一个元件，它可以是直接连接到另一个元件或者可能同时存在居中元件。本文所使用的术语“垂直的”、“水平的”、“左”、“右”以及类似的表述只是为了说明的目的。It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and similar expressions are used herein for illustrative purposes only.

除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。本文所使用的术语“及/或”包括一个或多个相关的所列项目的任意的和所有的组合。Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

实施例一Example 1

请参阅图1，所示为本发明实施例一中的LED外延片，包括蓝宝石衬底10、以及在蓝宝石衬底10上依次外延生长的所述缓冲层20、所述非掺杂GaN层30、所述n型GaN层40、所述多量子阱层50、所述电子阻挡层60，所述P型GaN层70。Please refer to FIG. 1 , which shows an LED epitaxial wafer in Embodiment 1 of the present invention, including asapphire substrate 10 , thebuffer layer 20 and theundoped GaN layer 30 epitaxially grown on thesapphire substrate 10 in sequence. , the n-type GaN layer 40 , the multiplequantum well layer 50 , theelectron blocking layer 60 , and the p-type GaN layer 70 .

在本实施例当中，非掺杂GaN层30为非Si掺杂BaGa1-aN层，a为0.005<a<0.1，其中，非掺杂GaN层30B组分从所述非掺杂GaN层30的一端向相对的另一端逐渐增加。由于非掺杂GaN层30等外延层的生长过程一般都是从衬底一侧向相对的另一侧逐渐生长，因此可以控制非掺杂GaN层30生成过程当中的B组合的通入量逐渐减少，继而制备得到B组分从一端向相对的另一端逐渐减少的非掺杂GaN层30，即这种非掺杂GaN层30的B组分呈现一边低一边高的情况。In this embodiment, the non-dopedGaN layer 30 is a non-Si-doped BaGa1-aN layer, and a is 0.005<a<0.1, wherein the composition of the non-doped GaN layer 30B is obtained from the non-dopedGaN layer 30 One end gradually increases towards the opposite end. Since the growth process of epitaxial layers such as theundoped GaN layer 30 is generally gradually grown from one side of the substrate to the opposite side, it is possible to control the amount of the B combination in the process of generating theundoped GaN layer 30 gradually. Then, theundoped GaN layer 30 with the B composition gradually decreasing from one end to the opposite end is prepared, that is, the B composition of theundoped GaN layer 30 is low on one side and high on the other.

示例而非限定，在本实施例一些较佳实施例当中，缓冲层20的厚度为10nm～30nm，例如为15nm、20nm、25nm等；非掺杂GaN层30的厚度为1um～5um，例如为2um、2.5um、3um等；n型GaN层40的厚度为2um～3um，例如为2um、2.5um、3um等；多量子阱层50可以为AlGaN层和InGaN层交替生长的周期性结构，InGaN层厚度可以为2nm～3.5nm，AlGaN层厚度可以为9nm～12nm，Al组分为0.1，堆叠周期为6～12个，例如为9个，即多量子阱层50共生长9层；电子阻挡层60的厚度为10nm～40nm，例如为20nm、25nm、30nm等；P型GaN层70的厚度为10nm～50nm，例如为20nm、30nm、40nm等。The thickness of thebuffer layer 20 is 10nm-30nm, such as 15nm, 20nm, 25nm, etc.; the thickness of theundoped GaN layer 30 is 1um-5um, such as 2um, 2.5um, 3um, etc.; the thickness of the n-type GaN layer 40 is 2um to 3um, such as 2um, 2.5um, 3um, etc.; the multiplequantum well layer 50 can be a periodic structure in which AlGaN layers and InGaN layers grow alternately. The layer thickness can be 2nm-3.5nm, the AlGaN layer thickness can be 9nm-12nm, the Al composition is 0.1, and the stacking period is 6-12, for example, 9, that is, themulti-quantum well layer 50 grows 9 layers in total; electron blocking The thickness of thelayer 60 is 10 nm to 40 nm, such as 20 nm, 25 nm, 30 nm, etc.; the thickness of the P-type GaN layer 70 is 10 nm to 50 nm, such as 20 nm, 30 nm, 40 nm, and the like.

实施例二Embodiment 2

请参阅图2，所示为本发明实施例二提出的一种LED外延片的外延生长方法，用于制备上述实施例一当中的LED外延片，所述方法具体包括步骤S201至步骤S207，其中：Please refer to FIG. 2 , which shows an epitaxial growth method of an LED epitaxial wafer proposed in the second embodiment of the present invention, which is used to prepare the LED epitaxial wafer in the above-mentioned first embodiment. The method specifically includes steps S201 to S207 , wherein :

步骤S201，提供一生长所需的蓝宝石衬底。Step S201, providing a sapphire substrate required for growth.

示例而非限定，在本实施例一些较佳实施例当中，衬底还可选用硅衬底、碳化硅衬底、氮化镓衬底、氧化锌衬底中的一种，在本实施例当中，衬底选用蓝宝石衬底，蓝宝石衬底在目前LED生产中广泛使用，蓝宝石衬底具有制备工艺成熟，价格低，化学稳定性好和热稳定性好等优点。It is an example but not a limitation. In some preferred embodiments of this embodiment, the substrate can also be selected from one of a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, and a zinc oxide substrate. In this embodiment, , The substrate is made of sapphire substrate. Sapphire substrate is widely used in the current LED production. The sapphire substrate has the advantages of mature preparation process, low price, good chemical stability and good thermal stability.

步骤S202，生长缓冲层，其生长厚度为10nm～30nm。In step S202, a buffer layer is grown, and the growth thickness thereof is 10 nm˜30 nm.

具体的，缓冲层的材料为AlN，该缓冲层在应用材料PVD中沉积于蓝宝石衬底上，在本实施例当中，AlN缓冲层的厚度为15nm。Specifically, the material of the buffer layer is AlN, and the buffer layer is deposited on the sapphire substrate in the applied material PVD. In this embodiment, the thickness of the AlN buffer layer is 15 nm.

步骤S203，生长非掺杂GaN层，其生长厚度为1um～5um。Step S203 , growing an undoped GaN layer with a growth thickness of 1um˜5um.

需要说明的是，采用中微A7 MOCVD(Metal-organic Chemical VaporDeposition)设备实现LED外延片的生长，在生长非掺杂GaN层时，所用到的源为高纯H2(氢气)、高纯N2(氮气)、高纯NH3(氨气)，其中，高纯H2和高纯N2作为载气，高纯NH3作为N源，BCL3作为硼源，三甲基镓(TMGa)及三乙基镓(TEGa)作为镓源。It should be noted that Zhongwei A7 MOCVD (Metal-organic Chemical VaporDeposition) equipment is used to realize the growth of LED epitaxial wafers. When growing the undoped GaN layer, the sources used are high-purity H2 (hydrogen), high-purity N2 ( Nitrogen), high-purity NH3 (ammonia), of which, high-purity H2 and high-purity N2 are used as carrier gas, high-purity NH3 is used as N source, BCL3 is used as boron source, trimethylgallium (TMGa) and triethylgallium (TEGa) ) as a gallium source.

具体的，非掺杂GaN层为掺杂B的BaGa1-aN材料，a为0.005<a<0.1，不掺杂Si，在生长非掺杂GaN层的过程中，控制B组分和N2/H2/NH3的混合气体通入，同时，控制B组分的通入流量由第一流量逐渐减小至第二流量，且控制N2/H2/NH3的混合气体中NH3的通入流量由第三流量逐渐减小至第四流量，以生长得到B组分从非掺杂GaN层的一端向相对的另一端逐渐减少的非掺杂GaN层，可以理解的，NH3浓度随着B的浓度升高而降低，可以减少B源与NH3的副反应，从而提升BaGa1-aN的晶体质量。Specifically, the undoped GaN layer is a B-doped BaGa1-aN material, a is 0.005<a<0.1, and is not doped with Si. In the process of growing the undoped GaN layer, the B composition and N2/H2 are controlled The mixed gas of /NH3 is introduced, and at the same time, the inflow rate of the B component is controlled to gradually decrease from the first flow rate to the second flow rate, and the inflow rate of NH3 in the mixed gas of N2/H2/NH3 is controlled from the third flow rate. Gradually reduce to the fourth flow rate to grow an undoped GaN layer in which the B component gradually decreases from one end of the undoped GaN layer to the opposite end. It can be understood that the NH3 concentration increases with the increase of the B concentration. If it is reduced, the side reaction between the B source and NH3 can be reduced, thereby improving the crystal quality of BaGa1-aN.

其中，非掺杂GaN层的生长压力为100torr～600torr，生长温度为1000℃～1200℃，在较高温度和较低压力下生长可以提高GaN的晶体质量，另外，GaN生长厚度越厚，压应力会通过堆垛层错释放，线缺陷减少，晶体质量越高，在本实施例当中，非掺杂GaN层生长温度为1100℃，生长压力150torr～200torr，生长出来的非掺杂GaN层厚度为2um～3um，在此厚度下，不仅晶体质量较优，而且节约了生产成本。Among them, the growth pressure of the undoped GaN layer is 100torr~600torr, and the growth temperature is 1000℃~1200℃. The growth at higher temperature and lower pressure can improve the crystal quality of GaN. In addition, the thicker the GaN growth thickness, the higher the pressure. The stress will be released through stacking faults, the line defects will be reduced, and the crystal quality will be higher. In this embodiment, the growth temperature of the undoped GaN layer is 1100 ° C, the growth pressure is 150torr to 200torr, and the thickness of the grown undoped GaN layer is It is 2um～3um, under this thickness, not only the crystal quality is better, but also the production cost is saved.

步骤S204，生长n型GaN层，其生长厚度为2um～3um。Step S204, growing an n-type GaN layer with a growth thickness of 2um˜3um.

在本实施例当中，n型GaN层生长温度为1100℃，Si掺杂浓度为1.6E19～5E19。In this embodiment, the growth temperature of the n-type GaN layer is 1100° C., and the Si doping concentration is 1.6E19˜5E19.

步骤S205，生长多量子阱层，其生长厚度为11nm～15.5nm。Step S205 , growing a multiple quantum well layer with a growth thickness of 11 nm˜15.5 nm.

具体的，多量子阱层为交替堆叠的InGaN量子阱层和AlGaN量子垒层，堆叠周期数6～12个，其中，InGaN量子阱层生长温度为790℃～810℃，厚度为2nm～3.5nm，AlGaN量子垒层生长温度为850℃～900℃，厚度为9nm～12nm，Al组分为0.1。Specifically, the multiple quantum well layers are alternately stacked InGaN quantum well layers and AlGaN quantum barrier layers, with 6 to 12 stacking periods, wherein the growth temperature of the InGaN quantum well layers is 790° C. to 810° C., and the thickness is 2 nm to 3.5 nm. , the growth temperature of the AlGaN quantum barrier layer is 850℃～900℃, the thickness is 9nm～12nm, and the Al composition is 0.1.

步骤S206，生长电子阻挡层，其生长厚度为10nm～40nm。Step S206 , growing an electron blocking layer with a growth thickness of 10 nm˜40 nm.

在本实施例当中，电子阻挡层为AlxInyGa1-x-yN层，生长温度为900℃～1000℃，其中Al组分浓度为0.005<x<0.1，In组分浓度为0.05<y<0.2。In this embodiment, the electron blocking layer is an AlxInyGa1-x-yN layer, the growth temperature is 900°C to 1000°C, and the Al composition concentration is 0.005<x<0.1, and the In composition concentration is 0.05<y<0.2.

步骤S207，生长P型GaN层，其生长厚度为10nm～50nm。Step S207, growing a P-type GaN layer with a growth thickness of 10 nm˜50 nm.

需要说明的是，P型GaN层生长温度为900℃～1000℃，生长压力为100torr～600torr，Mg掺杂浓度为1E19～1E20。It should be noted that the growth temperature of the P-type GaN layer is 900° C. to 1000° C., the growth pressure is 100 torr to 600 torr, and the Mg doping concentration is 1E19 to 1E20.

综上，本发明实施例当中的LED外延片及其外延生长方法，通过在非掺杂GaN层中掺入B组分，而B原子半径较小，可以填充GaN生长过程中晶格缺陷，改善GaN的晶体质量。此外，GaN刚开始生长晶体时，质量较差，缺陷较多，随着B组分浓度逐渐升高，B原子将会填充长晶产生的缺陷，且随着晶体厚度的增加，压应力会通过堆垛层错释放，线缺陷减少，晶体质量越高。To sum up, the LED epitaxial wafer and its epitaxial growth method in the embodiments of the present invention can fill the lattice defects in the GaN growth process by doping the B component in the undoped GaN layer, and the B atomic radius is relatively small. The crystal quality of GaN. In addition, when GaN crystal grows, the quality is poor and there are many defects. As the concentration of B component gradually increases, B atoms will fill the defects generated by the crystal growth, and as the thickness of the crystal increases, the compressive stress will pass through The stacking fault is released, the line defects are reduced, and the crystal quality is higher.

实施例三Embodiment 3

本发明实施例三提供一种LED芯片，包括上述实施例一当中的LED外延片，所述LED外延片可由上述实施例二当中的LED外延片的外延生长方法外延生长得到。The third embodiment of the present invention provides an LED chip, including the LED epitaxial wafer in the first embodiment. The LED epitaxial wafer can be epitaxially grown by the epitaxial growth method of the LED epitaxial wafer in the second embodiment.

将A样品和B样品使用相同芯片工艺条件制备成10mil*24mil芯片，其中A样品为目前量产制备得到的芯片，B样品为本方案制备得到的芯片，两个样品分别抽取300颗LED芯片，在120mA/60mA电流下测试，Ir良率(漏电良率)提升0.5％～1％，ESD良率(抗静电击穿良率)提升1％～3％，其他项电学性能良好。Sample A and sample B are prepared into 10mil*24mil chips using the same chip process conditions, where sample A is the chip prepared by current mass production, sample B is the chip prepared by this scheme, and 300 LED chips are selected from the two samples respectively. Tested at 120mA/60mA current, the Ir yield (leakage yield) is increased by 0.5% to 1%, the ESD yield (anti-static breakdown yield) is increased by 1% to 3%, and other electrical properties are good.

以上所述实施例仅表达了本发明的几种实施方式，其描述较为具体和详细，但并不能因此而理解为对本发明专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进，这些都属于本发明的保护范围。因此，本发明专利的保护范围应以所附权利要求为准。The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (9)

1. aN LED epitaxial wafer comprising aN undoped GaN layer, said undoped GaN layer being a B-doped BaGa1-aN material, a being 0.005 and being composed of a-s-0.1, wherein a B-component of said undoped GaN layer gradually increases from one end of said undoped GaN layer to the opposite other end.

2. The LED epitaxial wafer of claim 1, further comprising a sapphire substrate, a buffer layer, an n-type GaN layer, a multi-quantum well layer, an electron blocking layer, a P-type GaN layer;

the buffer layer, the non-doped GaN layer, the n-type GaN layer, the multi-quantum well layer, the electronic barrier layer and the P-type GaN layer are sequentially epitaxially grown on the sapphire substrate.

3. The LED epitaxial wafer of claim 2, wherein the buffer layer has a thickness of 10nm to 30nm, the undoped GaN layer has a thickness of 1um to 5um, the n-type GaN layer has a thickness of 2um to 3um, the MQW layer has a thickness of 11nm to 15.5nm, the electron blocking layer has a thickness of 10nm to 40nm, and the P-type GaN layer has a thickness of 10nm to 50nm.

4. The LED epitaxial wafer according to claim 2, wherein the mqw layer is a periodic structure in which AlGaN layers and InGaN layers are alternately grown.

5. An epitaxial growth method of an LED epitaxial wafer, for preparing the LED epitaxial wafer of any one of claims 1 to 4, the epitaxial growth method comprising:

and controlling the introduction of mixed gas of a B component and N2/H2/NH3 when growing the non-doped GaN layer, wherein the non-doped GaN layer is a B-doped BaGa1-aN material, and a is 0.005-a-0.1.

6. The epitaxial growth method of an LED epitaxial wafer according to claim 5, further comprising:

providing a sapphire substrate required for growth;

and sequentially epitaxially growing a buffer layer, a non-doped GaN layer, an n-type GaN layer, a multi-quantum well layer, an electronic barrier layer and a P-type GaN layer on the sapphire substrate.

7. The epitaxial growth method of the LED epitaxial wafer according to claim 5, wherein the step of controlling the introduction of the mixed gas of the B component and N2/H2/NH3 during the growth of the undoped GaN layer comprises:

and controlling the introduction flow of the component B to be gradually reduced from the first flow to the second flow, and controlling the introduction flow of NH3 in the N2/H2/NH3 mixed gas to be gradually reduced from the third flow to the fourth flow, so as to grow the non-doped GaN layer.

8. The epitaxial growth method of LED epitaxial wafer according to claim 5, wherein the growth pressure of the undoped GaN layer is 100-600 torr, and the growth temperature of the undoped GaN layer is 1000-1200 ℃.

9. An LED chip comprising the LED epitaxial wafer according to any one of claims 1 to 4.

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