Patent ID: 7879409
Filing Date: 2011-02-01
Classification: C23C

Abstract:
1. A method of controlling the average film thickness of a silicon oxide film deposited over a substrate having an area of at least 6,000 square centimeters, when a plurality of substrates are processed sequentially in a deposition chamber, comprising: a) depositing a nominal film thickness of said silicon oxide film over the surface of each of a first plurality of substrates which are sequentially processed in said deposition chamber, using a constant film deposition time period for each substrate; b) empirically determining an average film thickness for each of said first plurality of substrates; c) using said empirical film thickness data gathered from said first plurality of sequentially processed substrates to develop an algorithm based on a difference in average film thickness for each substrate in said first plurality of substrates, where the algorithm is a function of the substrate number in the sequence of substrates within said first plurality of substrates, and where the substrate average film thickness values used to develop the algorithm are limited to average film thicknesses where there is a trend toward increasing film thickness; and d) incorporating said algorithm into software which is used to control film deposition time period for a subsequently processed plurality of substrates which are sequentially processed, in a manner which maintains a consistent average film thickness during processing of at least 10 substrates.