Carrier Concentration Control of GaSb/GaInAsSb System

摘要

The residual carrier concentration of GaSb and GaSb-lattice matched Ga1-xInxAsySb1-y alloys (x = 0.12-0.26; y = 0.9x) grown by liquid phase epitaxy (LPE) and molecular beam epitaxy (MBE) was studied as a function of growth temperature, V/III ratio and alloy composition. Typical carrier concentrations p similar to 2-3x10(16) cm(-3) were obtained for undoped GaSb grown by MBE at 480 degrees C, by LPE from Ga-rich melt at low temperature (400 degrees C), and by LPE from Sb-rich melts at similar to 600 degrees C, The native acceptor defect responsible of the high p-type residual doping in GaSb is reduced when the indium concentration, is increased, and disappears for indium rich alloys (x = 0.23, 0.26). Tellurium compensation was used for controlled n-type doping in the (0.05-30)x10(17) cm(-3) range. A maximum of free carrier concentration was 1.5x10(18) cm(-3) for LPE layers, 2x10(18) cm(-3) for MBE layers grown at 1.0 mu m/h, 3.5x10(18) cm(-3) for MBE layers grown at 0.2 mu m/h. SIMS measurements showed Te concentrations of more than 1020 at/cm(3), suggesting the formation of ternary GaSb1-xTex solid solution.