电学性能不反常的本征GaAs基InSb异质外延研究

采用三步工艺进行了GaAs基InSb的异质外延生长并结合实验数据和文献资料研究了生长温度和速率、InSb层的厚度、低温缓冲层质量和双In源工艺对材料Hall电学性能等的影响。发现温度和生长速率对室温载流子迁移率和本征载流子浓度影响不太大;晶体XRD FWHM随膜厚的增加而逐渐地减小;低温缓冲层的界面质量和厚度对表面形貌具有一定的影响,低温缓冲层的界面厚度不应小于30 nm,ALE低温缓冲层的方法可以降低局部表面粗糙度;实验发现在优化的工艺参数基础上采用双In源生长工艺可以生长出电学性能不发生反常的理想本征InSb异质外延薄膜材料。获得2μm厚GaAs基InSb层在300 K和77 K的Hall迁移率分别为3.6546×104 cm^2 V^-1 s^-1和7.9453×104 cm^2 V^-1 s^-1,本征载流子迁移率和电子浓度随温度的变化符合理论公式的预期。

Study on intrinsic GaAs-based InSb heteroepitaxy with no abnormal electrical properties

In this paper,the heteroepitaxial growth of GaAs-based InSb was carried out by a three-step process,and the effects of growth temperature and rate,InSb layer thickness,low-temperature buffer layer quality and dual-indium source process on the electrical properties of Hall were studied in combination with experimental data and literature.It was found that temperature and growth rate had little effect on carrier mobility and intrinsic carrier concentration at room temperature.The crystal XRD FWHM decreased with the increase of film thickness.The interface quality and thickness of low-temperature buffer layer have certain influence on the surface topography.The interface thickness of low-temperature buffer layer should not be less than 30 nm,and the ALE low-temperature buffer layer method can reduce local surface roughness.It was found that the ideal InSb heteroepitaxial thin films without abnormal electrical properties could be grown by using the double indium source growth process on the basis of optimized process parameters.The Hall mobility of 2μm thick GaAs base InSb layer at 300 K and 77 K is 3.6546×104 cm^2 V^-1 s^-1 and 7.9453×104 cm^2 V^-1 s^-1,respectively.The change of intrinsic carrier mobility and electron concentration with temperature conform to the expectation of the theoretical formula.