Spectroscopic ellipsometry of pulsed laser irradiated c-Ge surfaces

摘要

Spectro-ellipsometric measurements were carried out on pulsed laser irradiated c-Ge surfaces. Numerical analyses indicated two possible parameterizations of the surface layer modeled by effective medium approximation. One solution was found for effective layer thickness of approximately 20 nm and Ge filling factor of approximately 7%. Effective layer thickness of second solution was approximately 8 nm and corresponding filling factor of Ge was approximately 53%. Surprisingly, the solution with small filling factor was found consistent with SEM measurement in which nano-dots were regularly arranged in one-dimensional parallel lines with the period of 1 μm.