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:
Nov. 03, 1992
Filed:
Mar. 11, 1991
Fuji Electric Co., Ltd., Kanagawa, JP;
Abstract
Herein provided is an electrostatic chuck whose surface is processed so as to have projections and recesses, which has a simple structure and which makes it possible to establish a uniform temperature distribution on a wafer surface when the wafer is held on the processed surface thereof through the use of an electrostatic attractive force. The uneven surface configuration of the electrostatic chuck is designed so that the proportion of the area occupied by the projected surface in the peripheral portion, i.e., in the relatively outer region of the surface, is smaller than that of the area occupied by the projected surface in the central portion, i.e., in the relatively inner region of the surface of the electrostatic chuck, in order to change the rate of heat transmission so as to be larger in the central portion than in the peripheral portion between the wafer and the electrostatic chuck. In this case, the height of the projections is limited to the range of from 10 to 70 .mu.m so as to perform effective control of the temperature distribution on the wafer by such adjustment of the proportion of the area occupied by the projections.