The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 2004
Filed:
Feb. 22, 2001
Alan D Marrs, Malvern, GB;
Allister W. E. Dann, Malvern, GB;
John L Glasper, Malvern, GB;
Christopher Pickering, Malvern, GB;
David J Robbins, Malvern, GB;
John Russell, Malvern, GB;
QinetiQ Limited, London, GB;
Abstract
Layer processing to grow a layer structure upon a substrate surface comprises supplying a vapor mixture stream to the substrate ( ) to deposit constituents, monitoring growth with an ellipsometer ( ) and using its output in real-time growth control of successive pseudo-layers. A Bayesian algorithm is used to predict a probability density function for pseudo-layer growth parameters from initial surface composition, growth conditions and associated growth probabilities therewith, the function comprising discrete samples. Weights are assigned to the samples representing occurrence likelihoods based on most recent sensor output. A subset of the samples is chosen with selection likelihood weighted in favor of samples with greater weights. The subset provides a subsequent predicted probability density function and associated pseudo-layer growth parameters for growth control, and becomes a predicted probability density function for a further iteration of pseudo-layer growth.