Patent ID: 7846846

Claim:
A method of performing plasma ion etching to form a high aspect ratio contact opening in a dielectric layer on a substrate, said method comprising: forming an aperture in a photoresist layer overlying the dielectric layer, said aperture defining a contact opening location and diameter; placing the substrate in a plasma reactor chamber; introducing into the chamber: a fluorocarbon or fluorohydrocarbon gas and Argon gas; etching a contact opening in said dielectric layer in registration with said aperture while depositing a polymer film on a side wall of said contact opening by coupling RF power into said chamber while continuously coupling to said substrate RF bias power of a nominal RF bias power level corresponding to a desired plasma etch process; and increasing conductivity of said polymer film on said side wall by ion bombardment of said polymer film with Argon ions, comprising coupling to said substrate successive bursts of RF bias power of a high RF bias power level in excess of more than 1.5 times said nominal power level.