利用In_(0.82)Ga_(0.18)As与InP衬底之间的应力制作结构材料的缓冲层

Preparation of Buffer by The Stress Between In_(0.82)Ga_(0.18)As Layer and InP Substrate

采用低压金属有机化学气相淀积(LP-MOCVD)技术,在InP(100)衬底上生长In0.82Ga0.18As,研究生长温度对In0.82Ga0.18As材料表面形貌、结晶质量和电学性能的影响。利用InP(100)衬底与In0.82Ga0.18As材料晶格失配所产生的应变,在不同的生长温度下应变释放程度不同,进而在In0.82Ga0.18As表面形成不同类型的缓冲层。分析不同的缓冲层对外延层In0.82Ga0.18As的影响,从而优化出最佳的生长温度。

In0.82Ga0.18As layers were grown on semi-insulating Fe-doped InP（100） substrates by low pressure metalorganic chemical vapor deposition（LP-MOCVD）.The growth was performed using TMIn,TMGa,and AsH3 as growth precursors of In,Ga,and As,respectively,in a horizontal reactor.The substrate on a graphite susceptor was heated by inductively coupling radio frequency power,the growth temperature was detected by a thermocouple,and the reactor pressure was kept at 1×104 Pa.Thickness of In0.82Ga0.18As layer for all samples was kept to be 300 nm.In our experiments,the growth temperature of In0.82Ga0.18As layers was 390,410,430,450,470,530 ℃,respectively.Because the strain caused by the lattice mismatch between In0.82-Ga0.18As layer and InP substrate was varied from the growth temperature,the surface of In0.82Ga0.18As layer was different.It was analyzed that the growth temperature of In0.82Ga0.18As layer influenced on the surface morphology,crystalline quality and the electrical property of the In0.82Ga0.18As layer.The surface morphology of In0.82Ga0.18As layer was studied by the scanning electron microscopy（SEM）.The components and crystalline quality of In0.82Ga0.18As layer were characterized by X-ray diffraction（XRD）.The electrical property of In0.82Ga0.18As layer was measured using the Hall Effect.This work shows a useful way how to design for the optimum buffer in growthing highly mismatched epitaxy layers.