CAJ | 학술논문

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5 nm的界面层.在经过400℃退火后,该界面厚度增加到约400 nm,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SAl参数降低且有效扩散长度LAi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SB参数和有效扩散长度LB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VGa相关缺陷的正电子捕获以及Gasb晶格反位引起的正电子浅捕获.X射线衍射的测量结果证实了正电子方法的结论.
용단능만정전자속화X사선연사방법연구료Al/n-GaSb금속반도체이질결재불동온도퇴화적정황하적연변.채용삼층모형기Al/계면/GaSb대S-E실험수거진행의합.결과발현재미퇴화양품적Al화GaSb지간존재일개후도대약5 nm적계면층.재경과400℃퇴화후,해계면후도증가도약400 nm,차S삼수하강.저가능시유우재퇴화과정중,계면구역적원자재계면처상호확산소인기적.Al막적SAl삼수강저차유효확산장도LAi증가,설명Al막내적공위결함경과퇴화피소제차진행결구중정,정격결구불단변호적결과.츤저GaSb적SB삼수화유효확산장도LB적연변표명,경과250℃퇴화후,원유적정전자포획중심소실;단시경진일보400℃퇴화,우산생료신적정전자포획중심.저가능래원우기타류형적여VGa상관결함적정전자포획이급Gasb정격반위인기적정전자천포획.X사선연사적측량결과증실료정전자방법적결론.
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 interfacial at the region between the Al layer and bulk in the sample of as-deposited. After the 400 ℃ annealing, this interfacial 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 Sb and Lb 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 VGarelated 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.