Patent ID: 6716476
Filing Date: 2004-04-06
Classification: C23C,G02B

Abstract:
A method of depositing an optical quality silica film by PECVD (Plasma Enhanced Chemical Vapor Deposition), comprising the steps of:a) independently setting a fixed flow rate for a silicon-containing raw material gas at a first value; b) independently setting a fixed flow rate for an oxidation gas at a second value; c) independently setting a fixed flow rate for a carrier gas at third value; d) independently setting a fixed flow rate for a dopant gas at a fourth value; e) independently setting a predetermined total deposition pressure at a fifth value; f) said first, second, third, fourth, and fifth values being selected by observing FTIR spectra of films deposited under different conditions and selecting values that result in minimal absorption peaks for oscillators in the deposited films; f) depositing a silica film using said selected values; and e) performing a post deposition heat treatment on said silica film at a temperature selected to minimize the mechanical stress induced in said film by said heat treatment.