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. 11, 2015
Filed:
Apr. 08, 2008
Shigeki Tozawa, Nirasaki, JP;
Yusuke Muraki, Nirasaki, JP;
Shigeki Tozawa, Nirasaki, JP;
Yusuke Muraki, Nirasaki, JP;
TOKYO ELECTRON LIMITED, Tokyo, JP;
Abstract
An etching method includes preparing a target object such that a first oxide film made of silicon oxide containing at least one of B and P is formed on a substrate, a second oxide film made of silicon oxide containing neither of B and P is formed on the first oxide film, and a contact portion is present below an interface between the first oxide film and the second oxide film. The etching method further includes etching the second oxide film and the first oxide film, thereby forming a hole reaching the contact portion, and etching the first oxide film by a dry process using a gas containing HF, thereby expanding a portion of the hole adjacent to an upper side of the contact portion and inside the first oxide film.