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:
Jun. 13, 1995
Filed:
Jun. 20, 1994
Roger A Robbins, Allen, TX (US);
Donald E Brown, Bedford, TX (US);
David W Buck, Mesquite, TX (US);
Alan D Rose, Wylie, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method and apparatus is provided for reducing wall erosion in a plasma containment tube (20), such as, for example, a quartz plasma tube (20) used in a microwave-induced plasma reaction process for etching semiconductor wafers. A pure benign or non-corrosive gas (Ar) is introduced into the 'upstream' section (22a) of the tube (22), where the microwave energy is imparted to create a plasma. The activated benign gas flows 'downstream' through a flange (28), preferably made of quartz, which is seated on o-rings (50) inside a water-cooled metal flange (48). These sealing o-rings (50) are thus cooled and removed from the ultraviolet light created by the plasma. The corrosive etchant gas (SF.sub.6) is introduced into the 'downstream' section (22b) of the tube (22) beyond the flange (28), where it is activated by the benign gas (Ar). The benign gas (Ar) flows principally along the inner sidewalls of the tube (22), and the etchant gas (SF.sub.6) is thus principally contained by the benign gas (Ar) in the center of this section (22b) of the tube. This 'downstream' section (22b) of the tube (22) is surrounded by a water jacket (24), which channels coolant around the outer surface of the tube (22b). Consequently, etching erosion of the inner surface of the tube (22) is minimized in the 'upstream' or microwave section (22a) where the plasma is hottest, and also in the 'downstream' section (22b) where the corrosive etchant gas (SF.sub.6) is activated.