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:
Jan. 27, 1998
Filed:
Dec. 07, 1995
Larry W Shive, St. Peters, MO (US);
Saeed Pirooz, St. Louis, MO (US);
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Abstract
Process for heat-treating a silicon wafer which includes the steps of contacting the surface of the silicon wafer with an aqueous solution containing hydrofluoric acid to remove metals from the wafer surface, contacting the hydrofluoric acid treated wafers with ozonated water to grow a hydrophilic oxide layer on the surface of the silicon wafer, and heating the ozonated water treated wafers to a temperature of at least about 300.degree. C. for a duration of at least about 1 second. The concentration of each of iron, chromium, calcium, titanium, cobalt, manganese, zinc and vanadium, on the surface of the silicon wafer at the initiation of the heating being less than 1.times.10.sup.9 atoms/cm.sup.2.