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:
Sep. 07, 1999
Filed:
Oct. 15, 1997
Masahiro Inohara, Tokyo, JP;
Tadashi Matsuno, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A method for fabricating a semiconductor device at low cost is provided in which a mask layer having a very large polishing selection ratio is used as a polishing stop film by forming the polishing stop film in self-alignment. An object layer to be flattened is formed on a substrate. The object layer contains an irregularity. A polishing stop film which is polished at a slower rate and a mask layer which is polished at about the same rate as the object layer are deposited on the object layer. Then, the mask layer on a high level portion of the object layer is removed by chemical-mechanical polishing. The polishing stop film is etched other than under the mask layer, so that the polishing stop film at the high level portion and side wall of the step is removed. Because the polishing stop film at the convex portions (high level portion) is removed by etching utilizing a chemical reaction without using chemical-mechanical polishing, it is possible to select a material for the polishing stop film which is polished at a very slow rate. After that, the mask layer and the object layer at the convex portion are removed by CMP to level off the object layer with the concave portion.