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. 18, 1988
Filed:
Aug. 26, 1987
Robert A Bowling, Garland, TX (US);
Wayne G Fisher, Allen, TX (US);
Edwin G Millis, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A method and apparatus is provided for removing submicron sized particles from the surface of a silicon semiconductor wafer (38). Conventional cleaning methods are capable of only removing particles that are about 1 micron or larger in size. The present invention provides a way to increase the submicron particles in size so that they are removable by the known methods. The silicon semiconductor wafer (38) is cooled by a refrigeration unit (36) or by exposure to liquid nitrogen (74). The cooled wafer (38) is then exposed to a condensable material (42) which is allowed to condense on the surface of the wafer (38). The condensable material will surround any particles that are on the surface and cause them to grow in size due to the formation of frozen crystals. Without allowing the crystals to melt, the enlarged particles then are removed by any of the known methods.