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:
Jun. 14, 1994
Filed:
Apr. 25, 1991
Arthur J Learn, Cupertino, CA (US);
Dale R Du Bois, Los Gatos, CA (US);
Nicholas E Miller, Cupertino, CA (US);
Richard A Seilheimer, Pleasanton, CA (US);
Silicon Valley Group, Inc., San Jose, CA (US);
Abstract
A chemical vapor deposition apparatus comprising a hot wall reaction tube, one or more reaction gas preheaters, a reaction gas exhaust outlet, and substantially eddy free reaction gas flow control means for passing reaction gases in a substantially laminar flow from a preheater to the exhaust outlet. The gas flow control means includes a tube flange positioned to be in a substantially eddy free relationship with the end of the wafer boat zone, the flange having a curved surface means extending from the end of the wafer boat zone to the outer tube for directing the reaction gas flow out of or into the reaction zone while maintaining the gas in a state of substantially laminar flow. One reaction gas preheater comprises a first heating tube having a removable baffle. A second reaction gas preheater comprises a two wall cylindrical heater with inner surface deformations. The two wall cylindrical heater and the heating tube each can have a plurality of gas injector ports with central axes positioned to cause immediate mixing of gases injected therefrom. An alternate reaction gas preheater comprises the passageway formed by concentric vacuum and reaction chamber tubes.