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:
Feb. 29, 2000
Filed:
Jul. 11, 1997
Robert D Mailho, Sonora, CA (US);
Douglas S Schatz, Fort Collins, CO (US);
Concept Systems Design, Inc., Fremont, CA (US);
Advanced Energy Industries, Inc., Fort Collins, CO (US);
Abstract
A structure and method are disclosed which allow for a tighter control of the temperature across a wafer substrate. In accordance with the present invention, a wafer to be processed is heated to a constant and uniform temperature by an RF induction coil including a plurality of heating zones each of which being shunted by an associated capacitor tuned to a specific frequency. By adjusting the time during which current of a particular frequency is provided to the induction coil, current flow within, and thus the heat generated in, each of the zones may be independently controlled. Since the heat generated in the susceptor quickly changes in response to changes in current flow therein, both deviations of the wafer temperature from the processing temperature and temperature gradients across the surface of the wafer may be quickly corrected. This superior thermal response results in the present invention maintaining a wafer at a uniform temperature during heating and cooling with increased accuracy and precision.