An AlN Sacrificial Buffer Layer Inserted into the GaN/Patterned Sapphire Substrate for a Chemical Lift-Off Process
An AlN Sacrificial Buffer Layer Inserted into the GaN/Patterned Sapphire Substrate for a Chemical Lift-Off Process
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DOI：
10.1143/apex.3.031001
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发表时间：
2010-01-01
影响因子：
2.3
通讯作者：
Huang, Yu-Chieh
中科院分区：
文献类型：
--
作者：
Lin, Chia-Feng;Dai, Jing-Jie;Huang, Yu-Chieh
通过化学剥离工艺，在GaN/蓝宝石衬底界面横向刻蚀AlN牺牲层，将生长在三角形图案化蓝宝石衬底上的InGaN基发光二极管（LED）分离。在外延生长之后，在蓝宝石衬底上的图案化区域处观察到空气空隙结构，其提供空的空间以增加AlN缓冲层的横向蚀刻速率。对于从蓝宝石衬底剥离的100 μ m宽的LED芯片，AlN缓冲层的横向蚀刻速率以10 μ m/min计算。在从图案化蓝宝石衬底转移的剥离GaN表面上观察到三角形孔结构和六边形空气空隙结构。与LED/蓝宝石结构相比，由于GaN/蓝宝石衬底界面处的压应变释放，在剥离的LED芯片上观察到了微光致发光光谱的峰值波长蓝移现象。化学剥离过程是通过在热的氢氧化钾溶液中使用AlN缓冲层作为牺牲层来实现的。(C)2010日本应用物理学会
InGaN-based light-emitting diodes (LEDs) grown on triangle-shaped patterned sapphire substrates were separated through a chemical lift-off process by laterally etching an AlN sacrificial layer at the GaN/sapphire substrate interface. After the epitaxial growth, an air-void structure was observed at the patterned region on the sapphire substrate that provided an empty space to increase the lateral etching rate of the AlN buffer layer. The lateral etching rate of the AlN buffer layer was calculated at 10 mu m/min for the 100-mu m-width LED chip that was lifted off from the sapphire substrate. A triangular-shaped hole structure and a hexagonal-shaped air-void structure were observed on the lift-off GaN surface that was transferred from the patterned sapphire substrate. Comparing to the LED/sapphire structure, a peak wavelength blueshift phenomenon of the micro-photoluminescence spectra was observed on the lifted off LED chip caused by the release of a compressive strain at the GaN/sapphire substrate interface. The chemical lift-off process was achieved by using an AlN buffer layer as a sacrificial layer in a hot potassium hydroxide solution. (C) 2010 The Japan Society of Applied Physics