Simulation of boron diffusion in strained Si/sub 1-x/Ge/sub x/ epitaxial layers

Abstract

This paper describes a simple and accurate model for boron diffusion in SiGe that was successfully implemented in TAURUS (PMEI). The comparison of the Si/sub 1-x/Ge/sub x/ samples to Si samples after rapid thermal and furnace annealing revealed a retarded B diffusion inside the strained Si/sub 1-x/Ge/sub x/ layers. The influence of the Ge content on the dopant diffusion was also measured and simulated, demonstrating that the B diffusion was found to decrease with the Ge alloy content. The model fits for various Ge percentages (both box and graded profiles) and thermal budgets. The simulation results of various Ge percentages and thermal budgets show good agreement with measurement data and the predicted B diffusivity show a reasonably low value.