Method of forming a self aligned contact (SAC) window

摘要

The present invention relates to a method of forming a self-aligned contact (SAC) window employing the liquid phase deposition (LPD) that allows low temperature deposition and selective growing of a LPD-SiO2 film as a stress-buffer layer to prevent WSi peeling during the formation of the SAC window. Specifically, the method comprises the steps of forming a nitride cap and a gate consisting of a WSi layer and a polysilicon layer over a surface of a silicon substrate followed by the formation of the sources and drain regions on the silicon substrate as well as by the process of forming the LPD-SiO2 film. A nitride spacer is formed at a sidewall of the nitride cap and the gate, and the SAC window is then formed by depositing a dielectric layer such as a SiO2 layer followed by exposing through a mask.