Some Aspects of Spreading Resistance Profile Analysis

Abstract

The calculation of resistivity profiles (and carrier density profiles) from spreading resistance requires the use of a correction factor. The present status of the calculation of the correction factor based upon the Schumann and Gardner multilayer solution of Laplace's equation is reviewed and discussed. Recent calculations of carrier densities from atomic densities are also discussed. In particular, the numerical solutions of the semiconductor equations are reviewed and their implications in the interpretation of spreading resistance measurements for profiling shallow layers are presented. The limitations of the multilayer Laplace equation analysis of spreading resistance in VLSI profiling are also discussed.

Recent Developments in the Interpretation of Spreading Resistance Profiles for VLSI‐Technology

“…profiles for a gaussian p-type implant into n-type substrate, one using our procedure, with Qsc = 0, and one taken from Albers (6). From this and many additional comparisons it is clear that the one-dimensional calculations provide essentially the same result as the two-dimensional ones, but with greatly increased computational simplicity.…”

“…An important factor to determine of course is whether this one-dimensional simulation resembles closely enough the two-dimensional configuration as encountered in practice. In order to evaluate this, we have compared our results with on-bevel carrier profiles calculated using twodimensional simulations (6). Figure 1 shows the calculated…”