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:
Oct. 14, 1997
Filed:
Oct. 29, 1993
Gregory W White, San Carlos, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
An apparatus and method for controlling the temperature of an object, in particular a semiconductor wafer support structure in a wafer processing chamber. A gas gap is created between the two adjacent objects of different temperatures. The pressure in the gap is adjusted to control the thermal conductivity of the gas between the two structures. To have a large heat flow between the two objects so that their temperatures can be closely matched, the pressure is increased. To maintain the temperature of the object sought to be controlled regardless of the temperature of the adjacent item (heat source/sink) the pressure is reduced to a strong vacuum (acting as insulation) so that very little heat flow occurs through the gas gap. Localized control acts together with a local heat sink to precisely control the temperature of a semiconductor support structure pedestal/cathode to maintain the uniformity of the temperature of the wafer during processing to prevent wafer surface process anomalies due to variations and gradients in temperature. Heating and cooling in one structure can be controlled by using alternating gas gaps. A heating heat source/sink is placed adjacent to a cooling heat sink/source both of which face the object whose temperature is to be controlled.