MOVPE 生长 Si δ 掺杂 GaAs/Al0.3Ga0.7As 异质结构及其霍耳测量

MOVPE Growth and characterization by hall effect easurement of Si δdoped GaAs/Al 0.3 Ga 0.7 As heterogeneous structure

使用自动变温霍耳测试系统测定了减压ＭＯＶＰＥ外延生长的硅δ掺杂ＧａＡｓ／Ａｌ０．３Ｇａ０．７Ａｓ异质结构，其在１５Ｋ和３００Ｋ时的电子迁移率分别为２．６×１０５ｃｍ２／Ｖ·ｓ和７３００ｃｍ２／Ｖ·ｓ，二维电子浓度分别为４．６５×１０１１／ｃｍ２和１．１７×１０１２／ｃｍ２，均比相同结构的生长体掺杂ＧａＡｓ／Ａｌ０．３Ｇａ０．７Ａｓ异质结构样品有很大提高，证实了使用δ掺杂技术取代体掺杂技术可以获得电学性能更佳的ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ异质结构．

The carrier mobilities and sheet concentrations of Si δ doped GaAs/Al 0.3 Ga 0.7 As heterostructures grown by low pressure MOVPE have been determined in the temperature range of 10～300K with a sophisticated automatic Hall measurement system.An electron mobility of 2.6×10 5cm 2/V·s and a sheet electron concentration of 4.65×10 11 /cm 2 were observed at 15K.And an electron mobility of 7300cm 2/V·s and a sheet electron concentration of 1.17×10 12 /cm 2 were observed at 300K.Both the mobility and sheet concentration are higher than those of MOVPE grown Si bulk doped GaAs/Al 0.3 Ga 0.7 As heterostructures with the same structure.It is demonstrated that.instead of bulk doping technique,a superior GaAs/Al xGa 1-x As heterostructure can be obtained by MOVPE δ doping technique.