Polarization of thin phosphosilicate glass films in MGOS structures

Abstract

An investigation has been made of the two polarization processes that occur in phosphosilicate glass films formed on thermally oxidized silicon. The MOS capacitance-voltage technique and ac measurements of capacitance and loss angle were used to investigate the component of the polarization that is operative at lower temperatures (i.e., ≲120°C). The magnitude of this component was found to increase quadratically with the P2O5 concentration of the glass film. The concentration dependence and related data were used to formulate a model for the low-temperature polarization. This model suggests that rearrangement of nonbridging oxygen ions is responsible for the glass polarization. The rate of glass polarization that occurs at higher temperatures (≳200°C) was found to increase very rapidly with increasing P2O5 concentration. It is shown that the polarization can be markedly reduced for practical applications by lowering the P2O5 concentration. © 1969 The American Institute of Physics.