The Effects of Capless Face-to-Face Annealing Temperature and Time on the Properties of Silicon Implanted Gallium Arsenide

Abstract

ABSTRACTMaintaining As overpressure during capless post-implantation annealing through the use of the face-to-face proximity configuration has proved to be a reproducible technique with less process parameters to control than the alternative techniques of capped or arsine annealing. An investigation of carrier mobility and dopant activation as a function of annealing temperature resulted in an optimum annealing temperature of 840 °C with activation improving for 9 min heat-up time as compared to a 14 min heat-up time. An increase in activation with anneal time during isothermal annealing was also observed. Dopant redistribution during annealing was modeled with an experimentally derived diffusion coefficient of 2×10−14 cm2/sec. This value is close to the diffusion coefficient published for capped annealing. Dopant redistribution in the near-surface (1000 Å) region was verified using SIMS. Based on presently available data there is no evidence for similar dopant redistribution during capless arsine annealing and this redistribution probably occurs whenever excess vacancy generation/redistribution is taking place, as during capped annealing and during proximity annealing.