Method and apparatus for low profile analysis of the near-surface, thin layers in silicon wafers

摘要

The wafer (1), or part of it, is oxidized on the examined side (2) to give a thin oxide layer (3), which is etched with dilute hydrofluoric acid. The thicknesses of the oxide layer and that of the original silicon layer are determined by differential weighing before and after etching. The etching solution is analyzed by a simple spectrometric method, to determine the concentration of contaminants in the layer. The process is repeated to determine the contaminant concentration at different determinable depths.