Patent ID: 8198103
Filing Date: 2012-06-12
Classification: H01L,Y10S

Abstract:
1. A method for etching a gate on a semiconductor wafer comprising: providing a semiconductor wafer having a photo resist layer with varying patterns with varying concentrations of hydrocarbons over a gate layer; providing said semiconductor wafer within a processing chamber; flowing an etchant into said processing chamber; contacting said etchant to said semiconductor wafer to generate varying concentrations of a hydrocarbon-containing reaction by-product across said varying patterns of said photo resist layer; determining a percentage of photo resist layer pattern differences across the semiconductor wafer; calculating an amount of a gas that compensates for said pattern differences using said percentage; adding said amount of gas within said processing chamber to compensate for said varying concentrations of said hydrocarbon-containing reaction by-product across said varying patterns by forming a homogeneous etchant having a uniform concentration of hydrocarbons across the entire said semiconductor wafer; maintaining said homogeneous etchant across said entire semiconductor wafer by controlling an amount of said hydrocarbon gas added to said processing chamber; etching a gate in said gate layer by contacting said gate layer with said homogeneous etchant; and simultaneously, depositing a passivation layer over all exposed surfaces during said etching using said homogeneous etchant having said uniform concentration of hydrocarbons to provide uniform etching results.