Etching method in a semiconductor processing and etching system for performing the same
View Patent ↗Disclosed is an etching method for semiconductor processing by which a pattern loading phenomenon is reduced. First, plasma is generated while setting a bias power applied to a wafer to zero and applying a source power. After a predetermined time period, an etching process is implemented onto a predetermined layer formed on the wafer by setting the bias power to a predetermined value. Since by-products generated during preceding etching processes can be readily removed during an etching using plasma, an etching process change due to a difference of pattern densities can be reduced. In addition, a progressive pattern loading generated as the number of processed wafers increase, can be prevented.
1. An etching method in a semiconductor processing comprising: forming a polysilicon layer, a tungsten silicide layer and an anti-reflective layer on a wafer;
generating plasma while setting a bias power applied to the wafer to zero and applying a source power for about 5 to about 90 seconds using a first processing gas of CF 4 /Ar;
executing an etching process onto the anti-reflective layer by setting the bias power to a first predetermined value;
generating plasma while setting the bias power to zero and applying the source power for about 5 to about 90 seconds using a second processing gas of Cl 2 /SF 6 ;
executing an etching process onto the tungsten silicide layer and the polysilicon layer by setting the bias power to a second predetermined value;
generating plasma while setting the bias power to zero and applying the source power for about 5 to about 90 seconds using a third processing gas of HBr/O 2 ; and
executing an etching process onto the polysilicon layer by setting the bias power to a third predetermined value.
2. An etching method as claimed in claim 1 , wherein different regions of the wafer having different pattern densities are formed after completing the etching process.
3. An etching method as claimed in claim 1 , wherein the generating plasma steps and executing an etching process steps are executed in-situ.