Approximation to impurity atom distribution from a two-step diffusion process

Abstract

The most commonly used diffusion process in planar technology is known as two-step diffusion, and the impurity atom profile is given by an integral. An approximation is suggested for such a profile which is simpler and accurate enough to be used in device characterization. It is seen that the built-in field resulting from two-step diffusion can be approximated as linearly varying with distance.