硅衬底GaN基LED异质外延生长及器件制备中应力研究

项目名称： 硅衬底GaN基LED异质外延生长及器件制备中应力研究

项目编号： No.61274039

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 张佰君

作者单位： 中山大学

项目金额： 92万元

中文摘要： GaN与硅之间大的晶格失配和热失配引起的应力问题是硅衬底GaN基LED外延生长及LED芯片制备中的主要问题。本项目拟围绕硅衬底GaN基材料生长及器件制备中的应力问题开展研究。在材料生长方面，采用微纳图形硅衬底及插入应力调控层技术，研究材料生长中的应力控制机制，解决硅衬底GaN基材料厚膜生长中的龟裂问题，并通过插入位错阻挡层降低位错密度，提高晶体质量；在硅衬底GaN基LED芯片制备中，采用多层金属电镀方法制备金属自支撑衬底来替代硅衬底，研究金属电镀条件、多层电镀金属结构及电镀金属的退火条件对GaN基薄膜材料应力的影响，解决硅衬底GaN基LED制备中的应力问题。这两个方面的研究对大尺寸硅衬底替代蓝宝石衬底，实现低成本LED芯片制备具有重要意义。

中文关键词： 氮化镓；硅衬底；发光二极管；应力；分布布拉格反射镜

英文摘要： The stress induced by the large lattice mismatch and the thermal expansion mismatch between GaN-based material and Si is the main problem for the GaN-based LED on Si substrate. In this proposal, our research is forcused on the issue of the stress in the GaN-based light-emitting diodes (LEDs) structure growth and the devices fabrication on silicon substrate. For the material growth, micro- and nano-patterned silicon substrate and the stress controlling layer will be used to avoid the generation of crack in thick GaN-based material. The mechanism of the stress controling will be investigated. The threading dislocation blocking layer will be inserted in the LED structure to reduce the dislocation density. In the devices fabrication,the metal plating techniqe will be adopted to form a free-standing metal substrate to instead of silicon substrate. In order to solve the problem of stress in the LED chip processing, multiple metals layers will be adopted. The effects of the metal plating condition, the structure of the multiple metal, and the annealing condition will be studyed in our research. To research the issue of stress in the material growth and the devices fabrication, it will play a key role in repleacing the sapphire substrate by large-scale silicon and in realizing the low cost for the GaN-based LEDs on sil

英文关键词： GaN；silicon substrate；light-emitting diode (LED)；Stress；Distributed Bragg reflector (DBR)