Determination of phosphorus in borophosphosilicate or phosphosilicate glass films on a silicon wafer by wavelength‐dispersive x‐ray spectrometry

Abstract

AbstractA wavelength‐dispersive x‐ray fluorescence method was developed for the determination of phosphorus in borophosphosilicate glass (BPSG) or phosphosilicate glass (PSG) films on a silicon wafer. Secondary spectral line intensities from the coated wafer are compared with those of an uncoated Si wafer and a fused P standard. The results are then converted to phosphorus content and surface density of the film by equations for the relative spectral line intensities of P and Si with corrections for the shift in the Si peak due to chemical bonding. Results obtained on an annealed set of PSG samples using four different incident spectra were self‐consistent and correlated well with independent inductively coupled plasma atomic emission spectrometric analyses for phosphorus and ellipsometric measurements of thickness. Preliminary results with BPSG samples were promising and showed that results for phosphorus were not sensitive to boron concentrations in the films.