非极性面GaN材料缺陷结构和组态的电子显微分析

项目名称： 非极性面GaN材料缺陷结构和组态的电子显微分析

项目编号： No.51302306

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 牛牧童

作者单位： 中国科学院苏州纳米技术与纳米仿生研究所

项目金额： 25万元

中文摘要： 由于可以回避沿载流子注入方向强极化电场的影响，非极性面GaN光电器件具有诸多优点。然而，高质量非极性GaN的异质外延生长异常困难，主要是贯穿外延膜的层错和位错密度非常高。尽管人们对非极性GaN中层错和位错类型进行了大量电镜表征，但对其起源、运动特性以及扩展机制还缺乏系统深入的认识。项目拟从GaN低温成核阶段形成的多种堆垛缺陷（层错）着眼，利用透射电子显微分析，结合阴极射线荧光表征以及位错滑移受力分析计算，系统研究多种MOCVD工艺策略生长的非极性GaN外延膜， 在不同生长阶段, 其内部各种层错之间，以及层错与位错之间的交互"诱生"作用, 深化人们对非极性GaN生长过程中层错、位错以及多种层错构成的"面缺陷网"的起源与扩展机制的认识，探究生长工艺对非极性GaN缺陷结构起源和扩展的影响机制，为非极性GaN材料及器件制备工艺的改进提供有针对性的参考依据。

中文关键词： GaN；AlN；TEM；位错；缺陷

英文摘要： Attribute to the absence of the polarization-related electric field along the carrier injecting direction, the nonpolar GaN-based optoelectronic devices possess many merits absent in their polar GaN counterparts. However, it is a big challenge to obtain high quality nonpolar GaN film, since both high density stacking faults and dislocations are inclined to generate within film during its epitaxial growth process.Although,many electron microscopic characterizations on stacking faults and dislocations have been conducted, the systematic and deep insights into their origin and propagation mechanism are still lacking.The project aims to carry out series defective structure investigations on GaN films of different growth status, prepared in a MOCVD system with different strategies, using electron microscopy as the main tool. Also,the Cathode Luminescence technique and mathematic analyzing on dislocation slipping behavior will be employed in the project to help us to obtain better understanding on the introduction and propagation mechanisms of various stacking faults and dislocations within GaN films fabriacted by different techniques, which is believed to be helpful and inspiring to the technique improvement of less defective nonpolar GaN material or device fabrication.

英文关键词： GaN；AlN；TEM；dislocation；defects