Theory of improved resolution in depth profiling with sample rotation

Abstract

We advance a theory that explains why sample rotation during depth profiling leads to a dramatic improvement in depth resolution. When the sample is rotated, the smoothing effects of viscous flow and surface self-diffusion can prevail over the roughening effect of the curvature-dependent sputter yield and generate a smooth surface. If the sample is not rotated initially and the depth resolution declines, we predict that subsequent rotation leads to improved resolution. This phenomenon has already been observed experimentally.