摘要
研究了Si在AlxGa1-xAs(0≤x≤1)中的掺杂行为.为比较Al組份对Si掺杂浓度的影响,在用气态源分子束外延生长(GSMBE)掺Si n型AlxGa1-xAs(0≤x≤1)的所有样品时,n型掺杂剂Si炉的温度恒定不变.用Hall效应测量外延层的自由载流子浓度和迁移率,用X射线双晶衍射迴摆曲线测量外延层的组份.测试结果表明,当AlxGa1-xAs中Al组份从0增至0.38时,Si的掺杂浓度从4×1018cm-3降至7.8×1016cm-3,电子迁移率从1900 cm2/Vs降至100 cm2/Vs.这与AlxGa1-xAs材料的Γ-X直接—间接带隙的转换点十分吻合.在AlxGa1-xAs全组份范囲内,自由载流子浓度隨Al组份从0至1呈“V”形变化,在X=0.38处呈最低点.在x>0.4之后,AlxGa1-xAs的电子迁移随Al组分的增加,一直维持较低值且波动幅度很小.
The doping behavior of Si in AlGaAs with AlAs mole fraction from 0 to 1 was reported. Si-doped Alx Ga1-x As layers were grown by gas source molecular beam epitaxy with a constant Si cell temperature for all samples. The electrical properties and composition of the ternary alloys were characterized by Hall effect and X-ray diffraction, respectively. Resuits show that the electron concentration of Si-doped Alx Ga1-x As varying with Al mole fraction has a minimum value at x = 0.38, which is the F-X direct-indirect band crossover of AlGaAs system. The Hall mobility decreases with the increasing of AlAs mole fraction till about x = 0.4, hereafter it remains at a low value of mobility with small change rate.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期1-4,9,共5页
Journal of Infrared and Millimeter Waves
基金
Supported by the National Natural Science Foundation of China(60136010,60676026,60406008)
National 973 Project of China(2006CB604903)
关键词
气态源分子束外延
ALGAAS
Si掺杂
电学性质
组分
gas source molecular beam epitaxy
Alx Ga1-x As
Si-doped
electrical properties
composition