Published online by Cambridge University Press: 28 February 2011
A buried p-layer in GaAs MESFET channel is successfully formed by (Si,Be) co-implantation and rapid thermal annealing process. The annealing cycle is optimized to activate Si and Be simultaneously and to minimize the dopant redistribution for precise dopant control. As a result, more than 80% activation efficiency for both Si and Be, as well as the greatly improved doping abruptness from 85 nm/decade to 65 nm/decade are achieved. Devices are fabricated and superior performance including sharper pinchoff, an increase of RF gain by 2–3dB and a 40% decrease in backgating effect is observed.