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. 21, 1994
Filed:
Dec. 21, 1992
Yoichi Mori, Kanagawa, JP;
Ebara Corporation, Tokyo, JP;
Ebara Research Co., Ltd., Fujisawa, JP;
Abstract
Halogen-containing waste gases resulting from the dry etching step of the process of fabricating semiconductor devices are rendered harmless by removing the halogen compounds concomitant with said waste gases. Waste gases containing halogen compounds are treated by bringing them into contact first with activated carbon and then into contact with a member selected from the group consisting of an alkali agent and a ferric oxide, at a linear velocity of about 3-50 cm/min at ambient temperature, volume ratios of said activated carbon to the alkali agent or the ferric oxide in terms of a substantially dried base being about 2-4, and said alkali agent being selected from a group consisting of calcium hydroxide, calcium oxide, magnesium hydroxide and magnesium oxide.