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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.
The evolution of Al / n-GaSb metal semiconductor heterojunction annealed at different temperatures was studied by single slow positron electron beam and X-ray diffraction. The SE experimental data were simulated using a three-layer model with both Al / interface and GaSb As a result, it was found that there was an interfacial layer of about 5 nm in thickness between the Al and the GaSb of the unannealed sample, and the thickness of the interfacial layer increased to about 400 nm after the annealing at 400 DEG C, and the S parameter decreased, probably due to the increase in annealing temperature , The interfacial diffusion of the atoms in the interface caused by the Al film S_ (Al) parameters decreased and the effective diffusion length L_ (Al) increases, indicating that defects in the Al film vacancies were removed by annealing and the structural reforming , The lattice structure is getting better results.SB substrate GaSb parameter and effective diffusion length L_B evolution shows that after annealing at 250 ℃, the original positron-trapping center disappears: but after further annealing at 400 ℃, and then produced The new positron capture center may be derived from other types of positron capture with V_ (Ga) -dependent defects and shallow positron capture by Ga_ (Sb) lattice inversion.The measurement of X-ray emission The conclusion of the positron method.