CN100389503C - Method for preparing LED chip with separate crystal grain vertical structure - Google Patents

Method for preparing LED chip with separate crystal grain vertical structure Download PDF

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CN100389503C
CN100389503C CN 200510011135 CN200510011135A CN100389503C CN 100389503 C CN100389503 C CN 100389503C CN 200510011135 CN200510011135 CN 200510011135 CN 200510011135 A CN200510011135 A CN 200510011135A CN 100389503 C CN100389503 C CN 100389503C
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led
growth
gan
substrate
epitaxial
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CN1801498A (en )
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丁晓民
于彤军
商淑萍
康香宁
张国义
杨志坚
山 祁
秦志新
童玉珍
胡晓东
羽 陆
陈志忠
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北京大学
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Abstract

本发明提出了一种高出光效率的管芯形状设计,通过岛状区域LED外延生长,生长分立晶粒LED芯片,激光剥离后将分立的LED芯片封装成上下电极的垂直结构的、具有较高光功率的LED的制备方法。 The present invention proposes to design a shape of the die above the optical efficiency by LED epitaxial island regions, growing a discrete vertical structure LED chip packages grains into upper and lower electrodes of the LED chip, after the release of discrete laser having a high light the production method of a power LED. 分立晶粒LED外延层,在岛状区域外延生长过程中,由于应力分布的改善,外延层中位错密度减少,晶体质量提高,从而提高了LED内量子效率。 Discrete grains LED epitaxial layer island regions in the epitaxial growth process, due to the improved stress distribution, the epitaxial layer reduces the dislocation density, to improve the crystal quality, thereby improving the quantum efficiency of the LED. 设计岛状区域的形状,使生长获得的晶粒几何形状为适合光导出的多边形、圆形,提高LED的光功率。 Design of the shape of the island regions, the growth of crystal grains obtained by the geometric shape suitable light derived polygon, circle, improved optical power LED. 由于岛状区域生长有利于应力的释放,在激光剥离过程中降低GaN和蓝宝石衬底界面处由于激光辐照而产生的应力,减少剥离过程中的损伤,减少剥离前后LED的发光光谱因应力变化而发生移动,以保证剥离衬底而获得高性能的LED。 Since the island regions growth conducive to the release of the stress, reducing the stress at the interface of GaN and the sapphire substrate by the laser radiation generated in the laser stripping process, to reduce the damage of the stripping process, reducing the LED emission spectra before and after the release of stress due to and moved to ensure separation substrate obtained by high-performance LED.

Description

分立晶粒垂直结构的LED芯片制备方法 Grain discrete LED chip production method of a vertical structure

技术领域 FIELD

本项发明属于光电技术领域,具体涉及结合金属有机物化学气相淀积 The present invention belongs to item photovoltaic technology, particularly to the bonding metal organic chemical vapor deposition

(MOCVD)外延生长技术、激光剥离和倒封装技术的一种功率型半导体发光二极管(LED )芯片的制备方法。 (MOCVD) epitaxial growth techniques, laser lift-off method for preparing a packaging technology and reverse power type semiconductor light emitting diode (LED) chips. 本发明提出一种通过生长直接获得分立晶粒LED 芯片的方法,提供LED芯片的几何图形设计不受LED芯片后工艺限制的新途径, 适用于获得新型、大功率LED的制备。 The present invention proposes a method of growing directly obtained by the discrete grains of the LED chip, a new route from process limitations to provide the LED chip geometry LED chip design for new, high-power LED preparation obtained.

背景技术 Background technique

通常,LED是在衬底上外延生长获得的,因而,LED的制备受到衬底晶体的晶格结构的制约。 Typically, LED epitaxial growth on a substrate is obtained, and thus, an LED prepared restricted crystal lattice structure of the substrate. 晶格失配、热膨胀系数的差异,使外延生长阶段的芯片外延层中应力积累和释放而产生大量的位错,特别对蓝宝石衬底上GaN基LED外延层来说,位错密度髙达10"Vcm2,从根本上制约了LED功率的进一步提高。在光导出方面,由于半导体折射率的与空气折射率差,抑制了光从半导体出射的效率,以及出光面的半导体材料吸收和金属电极层的吸收也不可忽視.另外,衬底的散热问题也大大地影响着功率型LED的特性。以上三方面成为影响功率型半导体LED芯片光功率主要因素. Lattice mismatch, the difference in thermal expansion coefficient of the stress accumulation and release phase epitaxial growth of the epitaxial layer chip generated a large amount of dislocations, in particular for GaN-based LED epitaxial layer on a sapphire substrate, the dislocation density of 10 Gao "Vcm2, restricting further improve fundamentally the LED power in light out, since the semiconductor and air refractive index difference is suppressed from the semiconductor light emission efficiency, and a semiconductor material and the surface of the metal electrode layer absorbent absorption can not be ignored. in addition, the heat dissipation problem of the substrate greatly influences the power LED characteristics become the above three aspects affect the power semiconductor LED chip light power factors.

芯片制备的后工艺一一划片裂片得到的LED形状和成品率,也普遍受村底上晶体结构的影响.对蓝宝石衬底上GaN基器件来说,更是由于蓝宝石的解理面与GaN外延层解理面不同而限制了芯片的形状,使有利于出光的管芯几何图形设计受到制约。 After the process for preparing the LED chip dicing eleven shape lobes and yield obtained, are generally affected by the crystal structure of the bottom of the village. Sapphire substrate for GaN-based devices, but also because the cleavage planes of sapphire and GaN different cleavage plane of the epitaxial layer is limited to the shape of the chip, so that the light dies in favor restricted geometric design. 另外,使用难于加工的衬底,增加了芯片制备的成本。 Further, use of the substrate are difficult to process, increases the cost of preparing chips.

目前,有很多报道降低外延层中位错密度,提高晶体质量的研究结果,主要为选择側向外延生长技术(LEO)和过渡层生长技术。 Currently, there are many reports to reduce the dislocation density in the epitaxial layer, to improve the crystal quality of the results of research, mainly the lateral epitaxial growth techniques for the selection (LEO) and buffer layer growth techniques. 日本的中村修二等人采用側向外延技术将源于衬底的贯穿位错密度降低了两个数量级,日本Kazuyuki Tadatomo等人图形化衬底上生长的LED外延层制备LED研究报道,位错密度降低为常规生长外延片的三分之一,而LED光功率提高近五倍,外量子效率达24%;日本名城大学赤崎勇研究组的M.Iwaya等人报道低温A1N插入层使张应 Nakamura in Japan who adopt second lateral epitaxy substrate from the threading dislocation density is reduced two orders of magnitude, LED grown on a prepared substrate LED epitaxial layer studies reported Japan Kazuyuki Tadatomo et al graphical dislocation density conventional epitaxial growth is reduced to one third sheet, and the LED light power is increased nearly five times, the external quantum efficiency of 24%; M.Iwaya Isamu Akasaki city university study group of Japan et al reported that the low-temperature tensile insertion layer A1N

力得到释放,获得了外延片上与位错对应的暗点密度降低到2X10、m^的好结果;T.Wang等人和CCYang等报道的多种緩冲层结构也给出了与位错对应的腐蚀坑密度达到106«11-2数量级的结杲表明晶休质量显著提高,并获得紫外光发光二极管(UVLED)功率大幅提高的良好结果. The strain relief is obtained on the wafer to reduce dislocation density of dark spots corresponding to 2X10, m ^ good results; T.Wang buffer layer structure more human like CCYang reported also gives the corresponding dislocations the etch pit density of 106 «Gao junction 11-2 show the order significantly improve the quality of the grain break, and ultraviolet light emitting diodes is obtained (the UVLED) good results in a substantial increase in power.

对于GaN基材料的异质生长来说,虽然側向外延生长技术(LEO)和过渡层生长技术能够改善晶体质量的机理还有许多不清楚的地方,但不能排除生长过程中应力的变化是一个重要因素。 For growth of the GaN heterostructure based material, the lateral epitaxial growth techniques, although the mechanism (LEO) and the buffer layer growth technique capable of improving the crystal quality there are many unclear, but the change can not be excluded growth process is a stress Key factor.

采用激光剥离技术,剝离蓝宝石衬底,制备垂直电极结构的GaN基LED, 已经成为一个值得关注的发展方向。 Laser lift-off technique, the sapphire substrate, a vertical electrode structure prepared in the LED GaN-based, has become a concern direction. 日本曰亚公司和德国的Osram公司已经推出该技术的相关设备。 Japan said Asian companies and the German company Osram has introduced the technology related equipment. 同时,倒封装结构的LED,由于避免了P电极和P-GaN 吸收,利用并且折射率低于GaN的蓝宝石面出光,已经证明能够使光功率明显提高,即使不剥离蓝宝石衬底,也能够大幅提高光功率1.5倍以上,美国Lumileds Lighting的丄J. Wierer等报告的结果以及Daniel Steigerwald等提出的专利US6573537B1表明倒装芯片出光效率提高1.6倍。 Meanwhile, the LED package structure inverted, since the electrode is avoided and P P-GaN absorption, and the use of lower refractive index than the light plane sapphire GaN, has proved capable of significantly improving the optical power, without peeling the sapphire substrate, it is possible to significantly increase the optical power of more than 1.5 times, the result of Lumileds Lighting US Shang J. Wierer Daniel Steigerwald and other reports proposed by patent US6573537B1 showed 1.6 fold improved flip-chip light-emitting efficiency.

我国台湾的JT Shu等进行了HVPE岛状选择生长LED的方法,观察到岛状生长区域的腐蚀坑密度(EPD)为l-5X107cm-2,说明岛状外延生长获得了很好的晶体质量,同时将LED外形做成六边形,使得LED的光功率为常规的非岛状生长的方型LED的两倍。 Taiwan JT Shu of the HVPE island-like LED selective growth method, the growth area was observed in the island-shaped etch pit density (EPD) of l-5X107cm-2, island-described epitaxial growth to obtain a good crystal quality, made of a hexagonal shape while the LED, the LED light power of a conventional non-square island growth of the LED twice.

因此,运用改善晶体质量的生长方法、结合倒封装、垂直结构LED的制备, 是提高LED光功率的主要方向。 Thus, using a method for improving crystal quality growth, combined inverted package, the vertical structure LED is prepared, to improve the main direction of the LED light power.

本项发明在上述研究基础上,提出一种不同的改变外延生长过程中应力分布以降低位错密度提高晶体质量,即MOCVD岛状生长,结合高出光效率的管芯形状设计和激光剝离技术,获得大功率LED芯片的简单、有效的新方法。 The present invention of the basis of these studies, we propose a different change in the stress distribution in an epitaxial growth process to reduce the dislocation density to improve the crystal quality, i.e., MOCVD island growth, higher light efficiency of the combined shape of the die and laser lift design, simple and effective new method for obtaining high-power LED chips.

发明内容 SUMMARY

本发明的目的是提出一种结合高出光效率的管芯形状设计,通过島状区域LED外延生长,生长分立晶粒LED芯片,激光剥离后将分立的LED芯片封装成上下电极的垂直结构的、具有较高光功率的LED的制备方法。 Object of the present invention is to propose a higher binding efficiency of light shaped to a die, island regions LED epitaxial growth, grain growth discrete LED chip after laser lift-off LED chip packages into discrete upper and lower electrodes of the vertical structure, the method of preparing an LED having a high optical power.

分立晶粒LED外延层,在岛状区域外延生长过程中,由于应力分布的改善, Discrete grains LED epitaxial layer, the epitaxial growth of the island-shaped region, the improvement due to the stress distribution,

外延层中位错密度减少,晶体质量提高,从而提高了LED内量子效率. The epitaxial layer reduces the dislocation density, to improve the crystal quality, thereby improving the quantum efficiency of the LED.

设计岛状区域的形状,使生长获得的晶粒几何形状为适合光导出的多边形、 圆形,提高LED的光功率。 Design of the shape of the island regions, the growth of crystal grains obtained by the geometric shape suitable light derived polygon, circle, improved optical power LED.

由于岛状区域生长有利于应力的释放,在激光剥离过程中降低GaN和蓝宝石衬底界面处由于激光辐照而产生的应力,减少剝离过程中的损伤,减少剝离前后LED的发光光谦因应力变化而发生移动,以保证剥离衬底而获得高性能的LED。 Since the island regions growth conducive to the release of the stress, reducing the stress at the interface of GaN and the sapphire substrate by the laser radiation generated in the laser stripping process, the stripping process to reduce the damage, reducing light emission before and after peeling the LED Qian moved by the stress changes to ensure separation substrate obtained by high-performance LED.

传统LED制备方法是MOCVD外延生长、电极制备、外延片减薄、分割获得芯片。 LED conventional MOCVD epitaxial growth is prepared, preparing an electrode, wafer thinning, chips obtained by the division. 本发明则在外延生长时即获得分立的LED晶粒,只需激光射离去除衬底和电极制备,即可获得LED芯片,无需减薄、分割等工艺过程,即可获得LED 芯片,与常规LED工艺相比,减少了后工艺,降^(氐了成本。 In the present invention, i.e. to provide discrete epitaxial growth of the LED die, leaving only the laser emitting substrate and the electrode prepared in addition, to obtain an LED chip, no thinning, segmentation process, the LED chip can be obtained with conventional compared LED technology, reducing the post-process, reducing ^ (Di cost.

本发明提出的岛状区域外延生长获得分立晶粒的垂直结构LED的方法,工艺过程简单,易于实现,是提高发光二极管效率的有效途径。 The method proposed by the present invention is obtained epitaxial island regions discrete vertical structure LED die, the process is simple, easy to implement, is an effective way to improve the efficiency of a light emitting diode.

该方法由于结合了激光剥离技术剥离蓝宝石衬底,制备成垂直结构的LED 芯片,而且芯片的形状设计为圃形和多边形,因而与JTShu等报道的岛状生长获得的LED芯片方法有着显著的不同. Since this method combines the laser lift the sapphire substrate to prepare a vertical structure LED chip, and the chip is shaped to garden shape and a polygon, and thus the island-shaped LED-chip method reported JTShu like growth obtained with significantly different .

本发明的分立晶粒垂直结构发光二极管的制备方法有以下几个要点: Preparing separate grain vertical structure light emitting diode of the present invention has the following points:

1. 在岛状区域外延生长分立晶粒LED外延层,区别于常规的整片生长和側向外延生长,将生长限制在芯片尺度的一定区域内。 1. In the discrete island regions grain LED epitaxial growth of the epitaxial layer, different from a conventional whole piece and lateral epitaxial growth, the growth limited to a certain area of ​​the chip scale.

2. 生长过程中应力分布改善,可以生长比较厚的外延层,外延层中位错密度减少,晶体质量提高。 2. The improved distribution of stress during growth can be grown relatively thick epitaxial layer, the epitaxial layer reduces the dislocation density, the crystal quality.

3. 在激光剥离过程中,岛状区域生长可以降低GaN和蓝宝石衬底界面处由于激光辐照而产生的应力,减少剥离过程中的损伤,减少剥离前后LED的发光光傳因应力变化而发生移动,以保证剝离衬底而获得髙性能的LED。 3. In the laser lift-off process, the island-shaped region growing stress can be reduced at the interface of GaN and sapphire substrate due to the generated laser irradiation, to reduce the damage of the stripping process, to reduce the LED-light emission due to stress release before and after a change occurs moving, to ensure performance to obtain a release Gao LED substrate.

4. 岛状区域的几何图形为适合光从管芯导出的多边形和圆形,从而实现了通过生长控制管芯形状和尺寸,越过了后工艺加工获得多边形和圓形管芯的困难,为管芯制备提供了一条新的途径。 4. The geometry of the island regions derived from the light suitable polygonal and circular die, thereby realizing the difficulties to obtain polygons, and circles crafting dies after growth by controlling the shape and size of the die, crossed, a tube preparing the core provides a new way.

5. 在外延生长时即获得分立的LED晶粒,只需激光剥离去除衬底和电极制备即可获得LED芯片,无需对蓝宝石或GaN减薄、分割等工艺过程, 即可获得LED芯片,与常规LED工艺相比,减少了后工艺的花费,降低了成本。 5. When epitaxial growth is obtained i.e. discrete LED dies, laser lift-off prepared simply removing the substrate and the electrode to obtain an LED chip without a sapphire or GaN thinning, splitting and other processes, to obtain an LED chip, and compared with the conventional LED technology, reducing the cost of the process and reduce costs.

根据本发明的分立晶粒垂直结构发光二极管的制备方法,具体技术方案有两种,下面详细说明各个技术方案的具体步骤: The preparation method of the present invention is a discrete grains vertical structure light emitting diode, two specific aspect, the specific steps of the various aspect of the detailed description below:

分立晶粒垂直结构的发光二极管芯片发光二极管的制备方法一,具体步猓 The method of preparing discrete LED chip light emitting diode die a vertical structure, specific steps Guo

如下: as follows:

1. 在蓝宝石衬底上淀积Si02,并刻蚀Si02以限定岛状生长区域和几何形状。 Deposited on a sapphire substrate 1. Si02, Si02 and etched to define a growth area and the island-shaped geometry. 将生长区的几何形状设计为有利于光导出多边形和圓形。 The growth zone geometry is designed to facilitate light derived polygons, and circles.

2. 在带有Si02图形的衬底上依次生长n型GaN、 LED有源层、p型GaN; 外延片还要进行常规的P型激活退火。 2. Si02 grown on the substrate with a pattern of sequentially an n-type GaN, LED active layer, p-type the GaN; epitaxial wafer also conventional activation anneal of the P-type.

3. 在p-GaN上制备电极和反射层,电极金属要能够获得良好欧姆接触,同时还要考虑到与起反射镜面作用的反射层金属有良好的粘附作用,淀积之后要经过合金而获得与p-GaN间的欧姆接触;反射层金属的选择为反射率高、稳定性好、与欧姆接触层金属有良好的粘附性,对欧姆接触无不良影响的金属。 3. After the reflective layer and the electrode prepared on the p-GaN, the electrode metal to be able to obtain a good ohmic contact, while also taking into account the effect of specular reflection from a reflective metal layer has a good adhesion, deposited alloy to go through obtaining ohmic contact between the p-GaN; selective reflective layer is a metal having high reflectance, good stability, the ohmic contact layer has good adhesion to metal, ohmic contact metal does not adversely affect.

4. 将上述带有P电极LED外延片利用金属层键合在Si或Cu支撑衬底上, 放置在真空室中抽走金属层中气泡,保证岛状生长层与支撑衬底表面均匀无空洞的紧密接触,支撑衬底加工成具有诱导裂片功能的图形。 4. The above-mentioned LED wafer with a P electrode using a metal layer bonded to the support substrate of Si or Cu, are placed in a vacuum chamber pumped bubbles in the metal layer, island growth to ensure that the support substrate surface layer with a uniform void-free close contact with the support substrate to have a processing function of the induced pattern lobes.

5. 激光剥离去除难于加工的蓝宝石衬底。 The laser lift-off removal of sapphire substrates are difficult to process. 由于GaN与蓝宝石衬底结合部分少,激光剥离中可以采用较低能量的激光束,减少了在剥离过程对界面处晶体的损伤。 Since the GaN and the sapphire substrate binding least partially, laser lift-off using a laser beam may be lower energy, reducing the damage to the crystal at the interface of the stripping process. 剥离完成后,需要去除外延层表面的金属Ga。 After stripping is completed, the need to remove the metal Ga surface of the epitaxial layer.

6. 在n-GaN面上完成n电极制备;由于出光面的要求,n电极要尽量占有较小的面积,通常在保证焊线的最低要求尺度上设计电极尺寸。 6. Preparation of n-electrode in the n-GaN surface is completed; because of the required surface, the n-electrode occupy a smaller area as far as possible, generally designed to ensure a minimum required size of the electrode wire bonding on the scale.

7. 分离岛状生长区域为垂直电极结构的LED芯片。 7. The isolated island growth region vertical electrode structure of the LED chip.

分立晶粒垂直结构的发光二极管芯片发光二极管的制备方法二,具体步骤 The method of preparing discrete LED chip light emitting diode die two vertical structure, specific steps

如下: as follows:

1.在蓝宝石衬底上淀积Si02,并刻蚀Si02以限定岛状生长区域和几何形 Deposited on a sapphire substrate 1. Si02, Si02 and etched to define a growth area and the island-shaped geometry

状。 shape. 将生长区的几何形状设计为有利于光导出多边形和圆形。 The growth zone geometry is designed to facilitate light derived polygons, and circles.

2. 在蓝宝石衬底上运用氢化物气相外延(HVPE)技术生长厚n-GaN外延层。 2. The use of hydride vapor phase epitaxy (HVPE) technique growing a thick n-GaN epitaxial layer on a sapphire substrate.

3. 在带有厚n-GaN岛状生长层的衬底上运用MOCVD技术二次生长Si掺杂GaN、 LED有源层、p型GaN,外延片还要进行常规的P型激活退火。 3. The use of MOCVD on a substrate having a thickness of island-grown n-GaN layer grown Si-doped second GaN, the LED active layer, p-type GaN, epitaxial wafer also conventional activation anneal of the P-type.

4. 在p-GaN上制备电极和反射层,电极金属要能够获得良好欧姆接触,同时还要考虑到与起反射镜面作用的反射层金属有良好的粘附作用,淀积之后要经过合金而获得与p-GaN间的欧姆接触;反射层金属的选择为反射率高、稳定性好、与欧姆接触层金属有良好的粘附性,对欧姆接触无不良影响的金属。 4. After preparation of the electrode and the reflective layer on the p-GaN, the electrode metal to be able to obtain a good ohmic contact, while also taking into account the reflective layer from a metal mirror acting with good adhesion, deposited alloy to go through obtaining ohmic contact between the p-GaN; selective reflective layer is a metal having high reflectance, good stability, the ohmic contact layer has good adhesion to metal, ohmic contact metal does not adversely affect.

5. 将上述带有P电极LED外延片利用金属层键合在Si或Cu支撑衬底上, 放置在真空室中抽走金属层中气泡,保证岛状生长层与支撑衬底表面均匀无空洞的紧密接触,支撑衬底加工成具有诱导裂片功能的图形。 5. The above-described epitaxial wafer with a P-electrode LED using a metal layer bonded support substrate of Si or Cu, are placed in a vacuum chamber pumped bubbles in the metal layer, island growth to ensure that the support substrate surface layer with a uniform void-free close contact with the support substrate to have a processing function of the induced pattern lobes.

6. 激光剥离去除难于加工的蓝宝石衬底。 6. The laser lift-off removal of sapphire substrates are difficult to process. 由于GaN与蓝宝石衬底结合部分少,激光剥离中可以采用较低能量的激光束,减少了在剥离过程对界面处晶体的损伤。 Since the GaN and the sapphire substrate binding least partially, laser lift-off using a laser beam may be lower energy, reducing the damage to the crystal at the interface of the stripping process. 剥离完成后,需要去除外延层表面的金属Ga。 After stripping is completed, the need to remove the metal Ga surface of the epitaxial layer.

7. 在n-GaN面上完成n电极制备,由于出光面的要求,n电极要尽量占有较小的面积,通常在保证焊线的最低要求尺度上设计电极尺寸。 7. Preparation of the n-electrode to complete the n-GaN surface, since the surface of the requirement, the n-electrode occupy a smaller area as far as possible, generally designed to ensure a minimum required size of the electrode wire bonding on the scale.

8. 分离島状生长区域为垂直电极结构的LED芯片。 8. An isolated island growth region vertical electrode structure of the LED chip. 上述两种方法,同样适用于外延层中带有AlGaN电子阻挡层的LED的制备。 Both methods are equally applicable to the preparation of the epitaxial layer with AlGaN electron blocking layer of the LED.

附图说明 BRIEF DESCRIPTION

下面结合附图对本发明进一步详细地说明: 图1岛状生长的平面几何图形结构; 图2 n型电极平面图; OF THE DRAWINGS The present invention is further described in detail: a planar geometric configuration diagram of island growth; n-type electrode 2 a plan view;

图3 (a) ~ (g)为分立晶粒垂直结构LED芯片制备过程; 图4 (a)和(b)分别示意Al和Ag的反射率与膜厚的关系。 FIG. 3 (a) ~ (g) for the preparation of discrete LED chip during a vertical grain structure; FIG. 4 (a) and (b) are a schematic of the reflectivity and the thickness of Al and Ag.

最佳实施例详细描述 Described in detail preferred embodiments

下面参照本发明的附图,更详细的描述出本发明的最佳实施例。 Referring to the drawings the present invention, a more detailed description of preferred embodiments of the present invention.

如图3(a) ~ (f)所示为分立晶粒垂直结构发光二极管芯片制备过程,图中1表示是蓝宝石衬底或带有GaN生长层的衬底,2是Si02, 3是LED外延片, 4是透明电极(Ni/Au ), 5是反射层,6是支撑村底(Si或Cu), 7是键合金属(Au-Sn 合金)。 As shown in FIG 3 (a) ~ (f) shown in a discrete light emitting diode chip preparation process of a vertical grain structure, represented in FIG. 1 is a sapphire substrate or the substrate having the GaN growth layer 2 is Si02, 3 is an LED epitaxial sheet, 4 is a transparent electrode (Ni / Au), 5 is a reflective layer, 6 is a bottom supporting village (Si or Cu), 7 is bonded to a metal (Au-Sn alloy). 下面结合附图详细说明最佳实施例一具体步骤: The following specific steps a detailed description of preferred embodiments in conjunction with the accompanying drawings:

(a) 在蓝宝石4于底1上淀积Si02 2,并刻蚀Si02 2以限定岛状生长区域和几何形状。 (A) a sapphire substrate 4 is deposited Si02 2 to 1, and etched to define Si02 2 island growth region and geometry. 生长区域的大小为LED器件尺寸,生长区的几何形状为有利于光导出多边形和圓形,图l中示例了矩形、六边形和圓形; The size of the growth area of ​​the LED device size, the geometry of the zone to facilitate the growth of the light derived polygons, and circles, Figure l illustrates a rectangular, hexagonal and circular;

(b) 在(a)步骤获得的衬底上,运用MOCVD技术生长LED外延层,并进行P型激活退火。 (B) on the substrate (a) obtained in the step, the use of LED epitaxial layers grown by MOCVD, an activation annealing and the P-type.

(c) 在GaN基LED外延片3 p面上蒸镀透明电极4,结构为Ni ( 50~100A) /Au ( 50 ~ IOOA ),然后在氧气氛中500°C下合金5分钟。 (C) a 3 p-plane of GaN-based LED epitaxial films deposited transparent electrode 4, the structure of Ni (50 ~ 100A) / Au (50 ~ IOOA), then the alloy in an oxygen atmosphere for 5 minutes at 500 ° C.

(d )在透明电极上蒸镀Ni( 50~100A )/Al( 300~500A )/Ni( 200A )/Au( 2000A) 反射层5。 (D) deposited Ni (50 ~ 100A) / Al (300 ~ 500A) / Ni (200A) / Au (2000A) reflective layer 5 on the transparent electrode. 反射层5中高反射率金属可以为Al或Ag,对应波长,可根据厚度与反射率关系进行调整。 The reflective layer 5 is a high-reflectance metal may be Al or Ag, the corresponding wavelength can be adjusted depending on the thickness-reflectance. 图4所示为对应于不同波长,Al层厚度和Ag层厚度与反射率的关系曲线图. FIG corresponding to a different wavelength, Al and the thickness of the Ag layer thickness and reflectance graph of Fig.

(e ) Si或Cu支撑衬底上制备Si02绝缘层,蒸镀Au-Sn合金或其他可用于键合的金属层7,并放置在真空室中抽走金属层7中气泡,保证岛状生长层与支撑衬底表面均匀无空洞的紧密接触,将支撑衬底加工成可以诱导裂片的图形及结构。 (E) Si or Cu support substrate was prepared Si02 insulating layer, deposited Au-Sn alloy, or other metal layers can be used for bonding 7, and placed in a vacuum chamber pumped metal layer 7 bubbles, island growth to ensure uniform void-free intimate contact with the support surface of the substrate layer, the substrate supporting structure may be processed into a pattern and induced lobes.

(f )在约300°C或更低的温度下下把LED外延片与Si衬底或铜衬底6键合。 (F) at about 300 ° C or lower temperatures the LED epitaxial Si substrate or copper sheet 6 bonded to the substrate.

(g) 用KrF准分子激光器从蓝宝石衬底侧照射,剥离蓝宝石衬底,激光器波长248nm,照射能量密度400-600 mJ/cm2,扫描频率为1Hz;剥离完成后,需要去除外延层表面的金属Ga。 (G) irradiating with KrF excimer laser from the sapphire substrate side, the sapphire substrate, the laser wavelength of 248 nm, irradiation energy density of 400-600 mJ / cm2, the scanning frequency of 1Hz; After stripping is completed, the need to remove the metal surface of the epitaxial layer Ga.

(h) 在n-GaN表面蒸镀n电极金属,经过图形剥离获得n电极;如图3所示为n型电极平面图,图中电极结构为Ti 200A /Al 200~300A /Ti 100~ 200A /Au 4000人。 (H) the vapor deposition surface of the n-GaN n-electrode metal, obtained after stripping the n-electrode pattern; FIG. 3 is a plan view of the n-type electrode, the electrode structure of FIG Ti 200A / Al 200 ~ 300A / Ti 100 ~ 200A / au 4000 people.

(i) 分离岛状生长区域,则获得大功率垂直电极结构的LED芯片。 (I) isolated island growth area, a vertical electrode structure is obtained high-power LED chips.

最佳实施例二技术方案如下,参考图3说明本实施例的具体步骤: (a)在蓝宝石4t底1上淀积Si022,并刻蚀Si022以限定岛状生长区域和几何形状。 Preferred technical solutions of the following two embodiments, with reference to FIG. 3 illustrate specific steps of the present embodiment: (a) depositing on a substrate of sapphire Si022 4t 1, Si022 and etched to define a growth area and the island-shaped geometry. 生长区域的大小为LED器件尺寸,生长区的几何形状为有利于光导出多边形和圆形,图1中示例了矩形、六边形和圆形。 The size of the growth area of ​​the LED device size, the geometry of the zone to facilitate the growth of the light derived polygon and a circle, in FIG. 1 illustrates a rectangular, hexagonal and circular.

(b )在(a )步骤中获得的衬底上,在蓝宝石衬底上运用氢化物气相外延(HVPE) 技术生长厚n-GaN外延层,获得岛状生长的n型GaN衬底。 (B) on the substrate obtained in step (a), the use of a hydride vapor phase epitaxy (HVPE) technique growing a thick n-GaN epitaxial layer on a sapphire substrate, an n-type GaN substrate to obtain an island growth.

(c )在(b )步骤获得的岛状GaN衬底上,运用MOCVD技术二次生长Si掺杂GaN、 LED有源层、p型GaN,外延片还要进行常规的P型激活退火。 (C) an island on a GaN substrate in step (b) is obtained, the use of MOCVD grown Si-doped GaN second, the LED active layer, P-type GaN, epitaxial wafer also conventional activation anneal of the P-type.

(d)在GaN基LED外延片p面上蒸镀透明电极4,结构为Ni ( 50A) /Au (50A ),然后在氧气下500°C下合金5分钟。 (D) In ​​the GaN-based LED epitaxial deposition surface of the substrate p transparent electrode 4, the structure Ni (50A) / Au (50A), then the alloy in oxygen 500 ° C 5 min.

(e )在透明电极上蒸镀Ni( 50~100A )/Al( 300~500A )/Ni( 200A )/Au( 2000A) 反射层5。 (E) vapor deposition Ni (50 ~ 100A) / Al (300 ~ 500A) / Ni (200A) / Au (2000A) reflective layer 5 on the transparent electrode. 反射层5中高反射率金属可以为Al或Ag,对应波长,可根据厚度与反射率关系进行调整。 The reflective layer 5 is a high-reflectance metal may be Al or Ag, the corresponding wavelength can be adjusted depending on the thickness-reflectance. 图4所示为对应于不同波长,Al层厚度和Ag层厚度与反射率的关系曲线图。 FIG corresponding to a different wavelength, Al and the thickness of the Ag layer thickness and reflectance graph of Fig.

(f) Si或Cu支撑衬底上1制备Si02绝缘层,蒸镀Au-Sn合金或其他可用于键合的金属层7,并放置在真空室中抽走金属层7中气泡,保证岛状生长层与支撑衬底表面均匀无空洞的紧密接触,将支撑衬底加工成可以谦导裂片的图形及结构6。 (F) Si or Cu is supported on the insulating layer 1 was prepared Si02 substrate, a metal layer is deposited Au-Sn alloy or other for bonding 7, and placed in a vacuum chamber pumped metal layer 7 bubbles, to ensure an island the growth layer having a uniform void-free intimate contact with the substrate surface of the support, the support substrate may be processed into a pattern and structure 6 is turned Qian lobes.

(g) 在约300°C或更低温度下把LED外延片与Si村底或铜衬底6鍵合。 (G) at about 300 ° C or lower sheet and the LED epitaxial Si village or bottom substrate 6 are bonded copper.

(h) 用KrF准分子激光器从蓝宝石衬底侧照射,剥离蓝宝石衬底,激光器波长248nm,照射能量密度400 -600 mJ /cm2,扫描频率为1Hz;剥离完成后,需要去除外延层表面的金属Ga。 (H) irradiation with KrF excimer laser from the sapphire substrate side, the sapphire substrate, the laser wavelength of 248 nm, irradiation energy density of 400 -600 mJ / cm2, the scanning frequency of 1Hz; After stripping is completed, the need to remove the metal surface of the epitaxial layer ga.

(i) 在n-GaN表面蒸镀n电极金属,经过图形剥离获得n电极;如图3所示为n型电极平面图,图中电极结构为Ti 200A /Al 200-300A /Ti 100~ 200人/Au 4000人。 (I) the n-electrode metal vapor deposition surface of the n-GaN, n obtained through the release pattern electrode; Ti 200A / Al 200-300A / Ti 100 ~ 200 shown in FIG. Persons n-type electrode 3 is a plan view of the electrode structure as shown in FIG. / Au 4000 people.

(j)分离岛状生长区域,则获得大功率垂直电极结构的LED芯片。 (J) separating island growth area, a vertical electrode structure is obtained high-power LED chips.

在以上对应两种分立晶粒垂直结构的发光二极管芯片的制备方法的制备方法的两个最佳实施例,外延生长步骤中增加AlGaN电子阻挡层或进行其他生长,将获得具有AlGaN电子阻挡层或其他外延结构的分立晶粒垂直结构的发光 In two preferred embodiments of the above two methods for the preparation of the corresponding discrete LED chip production method of a vertical structure of the grains, epitaxial growth step increase AlGaN electron blocking layer or other growth and obtain the AlGaN electron blocking layer, or a vertical structure light emitting discrete grains other epitaxial structure

二极管芯片,均可实施上迷分立晶粒垂直结构的发光二极管芯片的制备方法所迷的技术方案。 Diode chip can be implemented on a separate fan LED chip production method of a vertical structure of the grain aspect fans.

本項发明的优点: The advantages of the present inventions:

(1 )在岛状区域外延生长分立晶粒LED外延层,区别于常规的整片生长和側向外延生长,将生长区域限制在芯片尺度内,获得芯片尺寸的高质量島状LED 外延层。 (1) at discrete island regions grain LED epitaxial growth of the epitaxial layer, different from the conventional flood growth and epitaxial lateral overgrowth, growing area will be limited within a chip scale chip size to obtain high-quality epitaxial layer island-shaped LED.

(2) 生长过程中应力分布改善,可以生长比较厚的外延层,外延层中位错密度减少,晶体质量提高,使LED发光效率提高。 (2) improvement in stress distribution during growth, can be grown relatively thick epitaxial layer, the epitaxial layer reduces the dislocation density, to improve the crystal quality of the LED to improve light emission efficiency.

(3) 直接在島状图形衬底上实施与普通GaN-basedLED生长接近工艺,容易实现量产; (3) Embodiment ordinary GaN-basedLED growth close to the process, is easy to mass production island pattern directly on a substrate;

(4) 在激光剥离过程中,島状区域生长可以降低GaN和蓝宝石衬底界面处由于激光辐照而产生的应力,减少剥离过程中的损伤,减少剝离前后LED的发光光谱因应力变化而发生移动,以保证剥离衬底而获得高性能的LED。 (4) In the laser lift-off process, the island-shaped region growing stress can be reduced at the interface of GaN and sapphire substrate due to the generated laser irradiation, to reduce the damage of the stripping process, reducing the LED emission spectra before and after the release of stress due to changes in moves to ensure separation substrate obtained by high-performance LED.

(5) 岛状区域的几何图形为适合光从管芯导出的多边形和圓形,从而实现了通过生长控制管芯形状和尺寸,越过了后工艺加工获得多边形和圃形管芯的困难,为管芯制备提供了一条新的途径。 Geometry (5) for the island-like region is circular and polygonal light derived from the die, thereby controlling the growth achieved through the shape and size of the die, a process for processing the obtained crossed polygonal shape and difficult garden die for preparation die provides a new way.

(6) 在外延生长时即获得分立的LED晶粒,只需激光剝离去除衬底和电极制备即可获得LED芯片,无需对蓝宝石或GaN减薄、分割等工艺过程,即可获得LED芯片,与常规LED工艺相比,减少了后工艺的花费,降低了成本. (6) is obtained i.e. discrete LED dies during the epitaxial growth, a laser lift off just prepared substrate and the electrode is removed to obtain an LED chip without a sapphire or GaN thinning, splitting and other processes, to obtain an LED chip compared to the conventional LED technology, reducing the cost of the process and reduce costs.

(7) p型反射层采用高反射率的Al复合层结构,提高芯片出光效率。 (7) p-type reflective layer of Al with high reflectivity multilayer structure, improved light-emitting efficiency chip. 本项发明对GaN基大功率发光器件提供新的方法,尤其对短波长的发光二 The present inventions provides a new approach to high-power GaN-based light emitting device, particularly a short wavelength light emitting two

极管具有重要意义.应用该方法制备的LED,具有成为主流潜力的垂直电极结构,因而光功率和热学特性好,而且由于采用有利于光出射的管芯形状(圓形、 多边形),光功率会进一步提高.与目前报道的提高出光效率的方法相比,本发明所涉及的LED芯片制备工艺过程简单,有利于实现产业化。 Diode important application to the preparation of the LED, has become the mainstream of the potential of the vertical electrode structure, and thus good optical power, and thermal characteristics, but also thanks to facilitate the light exit die shape (circular, polygonal), the optical power is further improved compared with the method of improving the light efficiency reported to date, LED chip preparation process of the present invention is simple, conducive to industrialization.

尽管为说明目的公开了本发明的最佳实施例和附图,但是本领域的技术人员可以理解:在不脱离本发明及所附的权利要求的精神和范围内,各种替换、变化和修改都是可能的,因此,本发明不应局限于最佳实施例和附图所公开的内容。 While the disclosed embodiments and the accompanying drawings a preferred embodiment of the present invention are for illustrative purposes, those skilled in the art will be appreciated: in the present invention without departing from the appended claims and the spirit and scope of the various alternatives, modifications and variations are possible, therefore, the present invention should not be limited to the disclosure of preferred embodiments and the accompanying drawings.

Claims (1)

1.一种分立晶粒垂直结构的LED制备方法,具体包括以下步骤: 1)在蓝宝石衬底上淀积SiO2,并刻蚀SiO2以限定岛状生长区域和几何形状; 2)在刻蚀SiO2后形成图形的衬底上依次生长n型GaN、LED有源层、p型GaN,外延片还要进行常规的P型激活退火; 3)在p-GaN上制备电极和反射层; 4)将上述带有P电极LED外延片利用金属层键合在Si或Cu支撑衬底上, 放置在真空室中抽走金属层中气泡; 5)激光剥离去除蓝宝石衬底; 6)在n-GaN面上完成n电极制备; 7)分离岛状生长区域为垂直电极结构的LED芯片。 1. A method for preparing LED die discrete vertical structure, includes the following steps: 1) depositing on a sapphire substrate SiO2, and SiO2 is etched to define a growth area and the island-shaped geometry; 2) etching SiO2 after forming the pattern are sequentially grown on a substrate of n-type GaN, the LED active layer, p-type GaN, epitaxial wafer also conventional activation anneal of the P type; 3) and the reflective electrode layer prepared on a p-GaN; 4) the P with the above-described electrodes of the LED epitaxial wafer using a metal layer bonded support substrate of Si or Cu, are placed in a vacuum chamber pumped bubbles in the metal layer; 5) laser lift off the sapphire substrate is removed; 6) in the n-GaN surface preparation of the n-electrode is completed; 7) isolated island growth region vertical electrode structure of the LED chip.
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