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US 4,786,839 AGranted
Single crystal YAG color CRT
AssigneeAmerican Telephone and Telegraph Company, AT&T Bell Laboratories
InventorsTien-Wen Hou, Tai-Chan D. Huo
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Abstract
The target of a color CRT includes a plurality of color stripe triads which are oriented on a (111) surface parallel to the <112> crystallographic direction. The pattern of the stripe triads is etched using a SiO.sub.2 etch mask deposited directly on the YAG and an etchant comprising a hot mixture of sulfuric and phosphoric acids.
Claims6
In a color CRT, a target comprising
- a (111) oriented YAG substrate, and
- a plurality of epitaxial YAG layers grown on said substrate so as to be capable of generating a plurality of colors in response to an electron beam,
- at least one of said layers having the form of a stripe oriented essentially parallel to a <112>
- direction in the (111) plane to avoid axialmetric profile problems.
1 more element
A method of etching single crystal YAG comprising the steps of:
- depositing a SiO.sub.2 layer directly on said YAG,
- patterning said SiO.sub.2 layer to form openings, and
- subjecting the exposed portions of said YAG to a hot mixture of phosphoric and sulfuric acids.
Dependencies are inferred from the claim text.