Multi-range doping of epitaxial III-V layers from a single source

摘要

Silicon doping of GaAs epitaxial layers grown using the AsCl3/H2/GaAs:Ga CVD system is accomplished using AsCl3:SiCl4 liquid doping solutions. These solutions can be readily prepared with reproducible compositions and provide excellent doping control. Fine adjustments in the doping level can be achieved by adjusting the H2 flow rate and by varying the temperature of the doping solution. Doping levels may range from about 5x1015 to 5x1019 cm-3 by adjusting the mole fraction of SiCl4 in the doping solution and the H2 flow rate to change the mole fraction of PHCl. The epitaxial layers doped using this technique have excellent room temperature and liquid nitrogen mobilities for electron concentrations between 1x1016 cm-3 and 8x1018 cm-3. This doping method is particularly useful for the growth of GaAs epitaxial layers for FET devices.