Comparison of Measured and Simulated Two‐Dimensional Phosphorus Diffusion Profiles in Silicon

Abstract

The two‐dimensional diffusion of phosphorus has been studied by comparing profiles measured experimentally after furnace and rapid thermal annealing with simulated profiles obtained with the two‐dimensional simulators SUPREM IV and PREDICT 2. It was first shown experimentally that the effect of stress due to the window edge on chemical staining used in the measurement process is not significant to within the experimental error. It was then observed that there is considerable disagreement between measured and simulated profiles in the lateral direction, especially in the region directly under the mask edge. Possible explanations for the differences are discussed in terms of the inaccuracy of the initial implant simulation, the absence of damage annealing modeling in the simulation, and the effect of stress in the window edge vicinity on diffusion. When vacancy generation resulting from the reaction of the oxide with the underlying silicon substrate was included in the simulations, better agreement was observed with the experimental profiles.