Patent ID: 6914004

Claim:
A method for via etching in a dielectric material, comprising: providing a wafer having a substrate, a silicon carbide layer having a thickness of no more than approximately 500 angstroms disposed outwardly from the substrate, an Organo-Silica-Glass layer disposed outwardly from the silicon carbide layer, and a photoresist layer disposed outwardly from the Organo-Silica-Glass layer; positioning the wafer within a process chamber; introducing a first source gas mixture into the process chamber; etching a first portion of the Organo-Silica-Glass layer utilizing the first source gas mixture; introducing a second source gas mixture into the process chamber, the second source gas mixture comprising a fluorocarbon, argon, carbon monoxide, nitrogen, and oxygen; etching, for a time period between approximately thirty and ninety seconds, a second portion of the Organo-Silica-Glass layer down to the silicon carbide layer utilizing the second source gas mixture, the second source gas mixture having a volumetric flow rate of the fluorocarbon of between 2 and 20 sccm, a volumetric flow rate of the argon of between 100 and 400 sccm, a volumetric flow rate of the carbon monoxide of between 50 and 200 sccm, and a volumetric flow rate of the oxygen is less than 10 sccm, and a volumetric flow rate of the nitrogen that is sufficient to remove an ethyl group of the Organo-Silica-Glass at a rate that is at least as fast as the rate of removal of a silica group of the Organo-Silica-Glass; etching the silicon carbide layer; and cleaning the wafer.