Deposition and Reflow of Phosphosilicate Glass

Abstract

The chemical vapor deposition (CVD) and reflow of phosphosilicate glass (PSG) have been reviewed. The CVD reaction from silane and phosphine has been simulated by SOLGAS thermochemical calculations. This equilibrium calculation method predicts stoichiometric conversion of silane and phosphine. In comparison to experimental determinations, the calculations underestimate the glass phosphorus content by about 1–3 weight percent. In addition, recent observations that the reflow of PSG is greatly enhanced by the presence of a steam ambient during heating have been examined. A possible mechanism of this reflow enhancement has been discussed. Experimental evidence, which support this mechanism, by electron microprobe, FTIR, and SIMS studies of PSG films, are presented.