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:
Aug. 28, 2001
Filed:
Jun. 18, 1999
Yasuhiro Horiike and SpeedFam Co, Ltd., Tokyo, JP;
Abstract
A wafer flattening process and system enables a reduction of the surface roughness of a wafer resulting from local etching. A silicon wafer W is brought into close proximity to a nozzle portion,to feed SF,gas to an alumina discharge tube,, a plasma generator,is used to cause plasma discharge and spray a first activated species gas from the nozzle portion,to the silicon wafer W side, an X-Y drive mechanism,is used to make the nozzle portion,scan to perform a local etching step. Then the silicon wafer W is moved away from the nozzle portion,and O,gas and CF,gas are fed to the alumina discharge tube. At this time, the O,gas is set to be greater in amount than the CF,gas. When this mixed gas is made to discharge to generate plasma, a second activated species gas diffuses from the nozzle portion,to the entire surface of the silicon wafer W. Since there is a larger amount of O radicals than F radicals, the reaction product resulting from the O radicals deposit in fine depressions causing roughness and the front surface of the silicon wafer W is smoothed.