CARRIER CONCENTRATION AND COMPENSATION RATIO DEPENDENCE OF ELECTRON-DRIFT MOBILITY IN INAS1-XSBX

The electron mobility in InAs1-xSbx is calculated for an ionized impurity density between 5 X 10(14) cm-3 and 1 X 10(17) cm-3 at 77 K. The various methods of calculating electron mobility are discussed and their respective merits and limitations summarized. In general, alloy scattering is the mobility limiting process at low carrier density (n less-than-or-equal-to 10(15) cm-3) while ionized impurity scattering is important at higher carrier density. The effect of compensation (N(A)/N(D)) on low field drift mobility is also calculated for a range of carrier concentrations at x=0.1, 0.6, 0.9, and 1.0 compositions of particular technological significance. Compensation is found to degrade electron mobility quite significantly in all cases. The calculations at x=1.0 (InSb) are also found to be in good agreement with available experimental data.