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:
Dec. 22, 1998
Filed:
Mar. 25, 1994
David Cheng, Sunnyvale, CA (US);
Mei Chang, Cupertino, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
An improved apparatus for CVD processing is described wherein a wafer mounted on a vertically movable susceptor beneath a gas outlet or showerhead is raised into contact with a shield ring which normally rests on a ring support in the chamber. The shield ring engages the frontside edge of the wafer, lifting the shield ring off its support, when the susceptor and the wafer are raised to a deposition position in the chamber. The shield ring, by engaging the frontside edge of the wafer, shields the edge of the top surface of the wafer, as well as the end edge and the backside of the wafer, during the deposition. Matching tapered edges, respectively, on the susceptor and the shield ring permit alignment of the shield ring with respect to the susceptor, and alignment of the wafer to the susceptor and the shield ring. Alignment means are also disclosed to circularly align the shield ring to its support in the chamber. Multi-unit shield rings permit the use of wider shield rings and prevent cracking of the shield ring due to thermal stresses caused by temperature differences near and away from the wafer during processing. These shield rings may also have tapered edges to ensure alignment of the rings with respect to each other.