HOMOGENEOUS CHEMICAL ETCHING OF SAND-BLASTED SILICON SUBSTRATES

A simple chemical etching of silicon substrates in NaNO2-HF solutions allows us to obtain homogeneously luminescent surfaces when these subs trates are mechanically abraded by sand blasting. A comparative study of porous silicon prepared from non-abraded and sand-blasted wafers by IR spectrometry and thermal desorption spectrometry experiments is pe rformed vs. etching time. The hydrogen concentration is eight times hi gher in sand-blasted wafers and the configurations of the Si-H bonds a re different.