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:
Nov. 05, 2002
Filed:
Apr. 25, 2000
Steve I. Petvai, Wappingers Falls, NY (US);
Leslie Jane Bohnenkamp, Hopewell Jct., NY (US);
Michael P. Buet, New Fairfield, CT (US);
Beech Grove Technology, Inc., Wappingers Falls, NY (US);
Abstract
A method and apparatus for decomposing a layer of silicon oxide on a silicon wafer is described which employs the application of a heated mist of aqueous HF to the cooled wafer surface. The technique is applied to the analysis of silicon wafers for trace impurities using a scanning fluid drop to collect the residue containing the impurities after the silicon oxide has been decomposed. The novel method offers an order of magnitude increase in the rate of silicon oxide decomposition over the prior art which uses a vapor phase decomposition technique. In addition the novel method provides better control and safer disposition of the corrosive vapors over the prior art. The apparatus comprises a movable dome fitted with a carrier gas supply and a means for injecting a heated aqueous HF mist generated by a specially designed mist generator into the carrier gas flow. The flow mist droplets are drawn from the flow onto the cooled wafer surface providing a thin layer of liquid aqueous HF which reacts with the oxide layer at a faster rate than previously used HF vapor.