Patent ID: 6794303
Filing Date: 2004-09-21
Classification: H01L

Abstract:
A manufacturing method, comprising:providing a gate structure over a substrate; providing a silicon oxide layer over said gate structure and said substrate; providing a silicon nitride layer over said silicon oxide layer; providing a first gas flow including a first fluorocarbon and a second fluorocarbon at a first flowrate ratio of said first fluorocarbon to said second fluorocarbon, said first fluorocarbon having a higher ratio of fluorine atoms to carbon atoms than said second fluorocarbon; applying a first quantity of power to said first gas flow to create a first plasma and etching a first portion of said silicon nitride layer with said first plasma; providing a second gas flow including said first fluorocarbon and said second fluorocarbon at a second flowrate ratio of said first fluorocarbon to said second fluorocarbon greater than said first flowrate ratio of said first fluorocarbon to said second fluorocarbon; and applying a second quantity of power to said second gas flow to create a second plasma and etching a second portion of said silicon nitride layer with said second plasma, wherein the etching operations result in formation of silicon nitride spacers.