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. 12, 1989
Filed:
Apr. 15, 1988
Applicant:
Inventors:
Chorng-Tao Yu, Placentia, CA (US);
Michael A Fisk, Anaheim, CA (US);
Alan Emami, Huntington Beach, CA (US);
Assignee:
Thermco Systems, Inc., Orange, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
219390 ; 219411 ; 219388 ;
Abstract
A diffusion furnace and method for processing semiconductor wafers standing on edge wherein the furnace has vertically adjacent electrical resistance heating elements wired in parallel and disposed above the wafers. This arrangement enables the heat input to the furnace by the heating elements to be varied. In a preferred embodiment, the heating elements in the upper section of the tube are connected in one circuit and the heating elements in the lower section of the tube are connected in a second circuit and each circuit is controlled in response to the temperature in that section.