【摘要】 用单能慢正电子束和 X 射线衍射方法研究了 Al/n-GaSb 金属半导体异质结在不同温度退火的情况下的演变.采用三层模型既 Al/界面/GaSb 对 S-E 实验数据进行拟合.结果发现在未退火样品的 Al 和 GaSb 之间存在一个厚度大约5nm 的界面层.在经过400℃退火后,该界面厚度增加到约400nm,且 S 参数下降.这可能是由于在退火过程中,界面区域的原子在界面处相互扩散所引起的.Al 膜的 S_Al参数降低且效扩散长度 L_Al增加,说明 Al 膜内的空位缺陷经过退火被消除且进行结构重整,晶格结构不断变好的结果.衬底 GaSb 的 S_B 参数和有效扩散长度 L_B 的演变表明,经过250℃退火后,原有的正电子捕获中心消失：但是经进一步400℃退火,又产生了新的正电子捕获中心.这可能来源于其他类型的与 V_Ga相关缺陷的正电子捕获以及 Ga_Sb晶格反位引起的正电子浅捕获.X 射线衔射的测量结果证实了正电子方法的结论.更多还原

【Abstract】 Annealing study of the Al/GaSb system was performed by using a slow positron beam and the measurement of X-ray diffraction.The S parameter against positron energy data were fitted by a three layer model （Al/interface/GaSb）.It was found there was a～5 nm interracial at the region between the Al layer and bulk in the sample of as-deposited.After the 400℃ annealing,this interracial region extends to over 40 nm and S parameter dramatically drops.This is possibly due to a new phase formation induced by the atoms’ inter-diffusion at the interface.The annealing out of the open volume defects in the Al layer was revealed by the decrease of the S parameter and the increase of the effective diffusion length of the Al layer.Annealing behaviors of S_b and L_b of the GaSb bulk showed the annealing out of positron traps at 250℃.However, further annealing at 400℃ induces formation of positron traps,which are possibly another kind of V_Ga- related defect and the positron shallow trap GaSb anti-site.The results of the X-ray diffraction experiment verified the conclusion of obtained by using positron technology.更多还原