THEORY OF IMPROVED RESOLUTION IN-DEPTH PROFILING WITH SAMPLE ROTATION

We advance a theory that explains why sample rotation during depth pro filing leads to a dramatic improvement in depth resolution. When the s ample is rotated, the smoothing effects of viscous how and surface sel f-diffusion can prevail over the roughening effect of the curvature-de pendent sputter yield and generate a smooth surface. If the sample is not rotated initially and the depth resolution declines, we predict th at subsequent rotation leads to improved resolution. This phenomenon h as already been observed experimentally. (C) 1996 American Institute o f Physics.