Patent ID: 7393788

Claim:
A method of reducing a recess in a spacer etch process, comprising: disposing a silicon substrate having a spacer dielectric layer overlying a polysilicon feature and a single-crystal-silicon surface on a substrate holder in a dry plasma etching system; selecting a process condition to have an etch selectivity between said spacer dielectric layer and said single-crystal-silicon surface of greater than or equal to approximately 5-to-1, comprising: setting a pressure in said dry plasma etching system; introducing a process gas comprising a first flow rate of a noble gas, a second flow rate of CHF 3 , and a third flow rate of CH 2 F 2 ; and setting a power to be coupled to an electrode in said dry plasma etching system to form plasma from said process gas; applying said process condition to said dry plasma etching system; and exposing said substrate to said process condition to etch said spacer dielectric layer down to the single-crystal-silicon surface while minimizing a recess formed in said single-crystal-silicon surface.