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. 16, 1996
Filed:
Dec. 21, 1994
Edward T Siebert, New Fairfield, CT (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A method is disclosed for specifying the ratios of three or more coating materials so as to specify and control the index of refraction profile, stress profile, and/or the coefficient of thermal expansion of an optical coating. Also disclosed is a coating deposition chamber (10) that includes an in-situ stress monitor (12) for measuring a stress within a coating (20). The output of the monitor is compared to predicted profiles and appropriate corrections are made to chamber constants. In a presently preferred embodiment, the in-situ stress monitor includes an interferometer having a sample beam (28a) that reflects from a surface of a substrate (22) upon which the coating is being formed. A change in the optical path length is indicative of a direction and magnitude of a substrate flexure due to stress induced in the coating. Responsive to the determined stress, coating chamber operating parameters are varied, if required, to maintain the stress at a desired magnitude and type.