STUDY OF 2-DIMENSIONAL HOLE GAS CONCENTRATION AND HOLE MOBILITY IN ZINC DELTA-DOPED GAAS AND PSEUDOMORPHIC GAAS IN0.2GA0.8AS HETEROSTRUCTURES/

Zinc delta-doped GaAs and pseudomorphic GaAs/In0.2Ga0.8As heterostruct ures grown by low-pressure metalorganic chemical vapour deposition hav e been demonstrated. The influence of delta-doping period and spacer t hickness on two-dimensional hole gas concentrations and hole mobility was studied. From secondary-ion mass spectroscopy and Hall measurement , we conclude that zinc delta-doping can form an excellent abrupt prof ile (full-width at half maximum is of 10 nm) and offer a high two-dime nsional hole gas sheet density (as high as 1 x 10(13) cm(-2)). By adop ting a strained InGaAs material as the active channel and by carefully modulating the spacer layer thickness, one can obtain a significantly enhanced hole mobility. (C) 1998 Academic Press.