Auger and ellipsometric study of phosphorus segregation in oxidized degenerate silicon

Phosphorus redistribution during thermal oxidation of degenerately doped silicon was investigated using Auger electron spectroscopy and ellipsometry. Concentration profiles were determined with a combination of chemical and sputter etching techniques. A substantial phosphorus pileup was observed in the oxide in a thin layer near the ellipsometrically determined SiSingle Bond signSiO2 interface. Calibrated against standards of known concentration, this layer was found to contain ∼2×1021 phosphorus atoms/cm3, independent of the oxidation temperature between 850 and 1000°C. © 1974 American Institute of Physics.