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. 20, 2000
Filed:
Mar. 27, 1997
Miyuki Takenaka, Kanagawa, JP;
Yuji Yamada, Kanagawa, JP;
Masaru Hayashi, Kanagawa, JP;
Hideki Matsunaga, Kanagawa, JP;
Akira Okada, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Disclosed is a method and an apparatus for etching a silicon material in order to prepare a sample for measuring the impurities which are contained in the silicon material. The silicon material is etched by contacting the silicon material with an etching gas containing a fluorine compound which is selected from the group consisting of xenon fluoride, hydrogen fluoride, oxygen fluoride and halogen fluoride, to produce a product by reaction of the silicon material with the etching gas. The product is heated to evaporate and remove the product from an impurity which is contained in the silicon material and not reactive to the etching gas.