Measurement of phosphorus content in silica layers

Abstract

The phosphorus contents in the thin protective layers of P2O5 +SiO2 on a number of silicon wafers were measured by using both PIXE and RBS techniques. Analyzing the two sets of data with the assumption of a uniform distribution of phosphorus in the oxide layer yielded an apparent discrepancy. It was found by computer simulation that the discrepancy could be removed by introducing nonconstant depth profiles of phosphorus in the analysis of the RBS data. A similar investigation also revealed that PIXE analysis was not sensitive to the phosphorus depth profile. © 1993.