ETCH PROCESS HAVING ADAPTIVE CONTROL WITH ETCH DEPTH OF PRESSURE AND POWER

摘要

The disclosure concerns a plasma-enhanced etch process in which chamber pressure and/or RF power level is ramped throughout the etch process.

主权项

1. A method of processing a workpiece in a plasma reactor chamber, comprising:
defining a starting chamber pressure; defining an ending chamber pressure at which a desired etch selectivity of an etch process to an underlying barrier layer is realized; defining an etch time; computing a pressure ramping rate as a difference between said starting and ending chamber pressures divided by said etch time; providing in said chamber a plasma containing etchant species; initializing a chamber pressure in said chamber at said starting chamber pressure; and ramping said chamber pressure at said pressure ramping rate.