Process design and optimization of the channel doping profile in power

In this paper the procedure for the process design of the channel doping profile in low-voltage power VDMOSFETs is presented. An optimization of some of the process parameters having greatest influence on the shape of the channel doping profile, is briefly described. Effects of the variation of the p-body diffusion time on the threshold voltage and channel length are discussed in particular. It is shown that the threshold voltage sensitivity due to variations of p-body diffusion time can be minimized by appropriate adjustment of the source diffusion in the lateral direction. The results obtained show qualitatively good agreement of the two-dimensional process and device simulation with the design rules.