基于肖特基电流输运模型和扫描分布电阻显微术的窄量子阱载流子浓度表征

目前对于纳米尺度半导体材料的局域电导与对应载流子浓度关系的描述主要以参数拟合为主。其关系模型主要依赖人工拟合参数, 例如理想因子。所以无法从测得局域电导分布来推出载流子浓度分布。为此, 提出了一种获取量子阱中载流子浓度的模型。通过小于10nm分辨的截面扫描分布电阻显微术, 测得了GaAs/AlGaAs量子阱 (110) 截面的局域电导分布。基于实验设置, 提出了只含有掺杂浓度参量的实验描述模型。通过模型, 由测得的量子阱 (掺杂浓度从1016/cm3到1018/cm3) 局域电导分布, 推导出了其载流子分布。相对误差在30%之内。

D-carrier profiling in narrow quantum wells by a Schottky's current transport model based on scanning spreading resistance microscopy

Current studies on the relationship between carrier concentration in nano-scale semiconductor structure and its local conductance is mainly on parameters fitting.For above connection, existing models rely on artificial fitting parameters such as ideal factor.For above reason, derivation of carrier concentration though measured local conductance can not be done.In this work, we present a scheme to obtain the carrier concentration in narrowquantum wells (QWs) .Cross-sectional scanning spreading resistance microscopy (SSRM) provides unparalleled spatial resolution (< 10 nm, Capable of characterizing single QW layer) in electrical characterization.High-resolution local conductance has been measured by SSRMon molecular beam epitaxy-grown GaAs/AlGaAs QWs cleaved surface (110) .Based on our experimental set-up, a model which describes conductance by the only argument, i.e.carrier concentration has been built.Using the model, our implementation derived carrier concentration from SSRMmeasured local conductance in GaAs/AlGaAs QWs (doping level:1016/cm3-1018/cm3) .Relative errors of the results are within 30%.