Patent ID: 6221772
Filing Date: 2001-04-24
Classification: C11D,G03F,H01L

Abstract:
A method of in-situ cleaning polymers in holes on a semiconductor wafer; the semiconductor wafer comprising a substrate, a silicon nitride (Si.sub.3 N.sub.4) layer on the substrate, a silicon oxide (SiO.sub.2) layer on the silicon nitride layer, and a photo-resist layer on the silicon oxide layer; the silicon oxide layer and the photo-resist layer having a hole extending down to the silicon nitride layer, the hole containing polymer left by etching of the silicon oxide layer, the method comprising:performing a in-situ plasma ashing process by injecting oxygen (O.sub.2) and argon (Ar) to completely remove the photo-resist layer and the polymers remaining within the contact holes, the flow rate of O.sub.2 being maintained between 50.about.2000 sccm (standard cubic centimeter per minute) and the flow rate of Ar being maintained between 50.about.500 sccm.