中文摘要：

用化学腐蚀法、金相显微观察、透射电镜（TEM）、电子探针X射线微区分析（EPMA）和扫描电镜能谱分析（EDX）等手段，对φ76mm非掺杂（ND）半绝缘砷化镓（SI-GaAs）单晶中微缺陷、碳的微区分布进行了分析。结果表明：在晶体周边区域，由高密度位错运动和反应形成胞状结构，该胞状结构的本质就是晶体结晶时形成的小角度晶界，且位错与微缺陷有强烈的相互作用：杂质碳在胞壁、近胞壁和完整区的含量依次降低，存在条纹分布。

英文摘要：

The micro-defects and impurities distribution in φ76 mm nondoped-semi-insulating-GaAs （ND-SI-GaAs） were investigated by means of chemical etching method, metallographic microscope, TEM, EPMA and EDX. The results showed that the movement and reaction of high dense dislocation formed cell structures, which were the small angle grain boundary formed during crystal. Dislocation and micro-defects interacted strongly each other. Carbon impurity concentration decreased from cell wall, vicinity of cell wall to denuded zone sequentially and striation distribution existed.