Nitride cap sidewell oxide protection from BOE etch

摘要: A new method of forming a self-aligned contact is achieved. pattern polysilicon gate electrode stack including silicon oxide dielectric, electrode, first thermal polyoxide layer over the top said layer, nitride and TEOS provided on substrate. Each layers has its side open to ambient. Inert ions are implanted into substrate which not covered by in such manner as reduce possibility oxidation surface The subjected oxidizing ambient causes sides form second layer. formed anisotropically etched remove from while leaving remaining upon opening regions within self-aligning through opening.