Measurement and simulation of boron diffusivity in strained Si/sub 1-x/Ge/sub x/ epitaxial layers

Diffusion of dopants in a crystalline Si and Ge is an example where controlled experiments in pristine material have led to complex, phenomenological models. These models, although limited in their absolute prediction of diffusivity, do provide a guide for predicting the change of diffusivity with certain material properties including Ge fractions, chemical effects etc, and physical parameters including temperature etc. A simple and accurate empirical diffusion model that fits for various Ge concentrations and thermal budget is developed and implemented in a TAURUS-PMEI (Physical Model and Equation Interface). The present diffusion model accurately simulates the measurement profiles over the range of Ge concentrations, and box and graded Ge profiles that were selected as experimental conditions involved in the present study.