Ultra shallow junctions formed by sub-melt laser annealing

Abstract

Since the requirements for the S/D extensions for future devices become more and more severe with respect to activation and vertical abruptness, a huge effort has been done to develop ultra-fast annealing techniques such as laser annealing. Due to the fact that only the surface layers are heated, the Si wafer serves as a heat sink. Hence, extremely fast cooling rates can be obtained resulting in a high activation and limited diffusion of the dopants. We present a preliminary study on the activation of n- and p-type junction implants by sub-melt laser annealing. The influence of the pre-amorphization depth, the laser annealing temperature and other process parameters on the activation has been investigated. Sheet resistance and junction depth measurements reveal good activation with minimal diffusion