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:
Feb. 20, 1990
Filed:
Jun. 07, 1988
Tatsuo Okamoto, Itami, JP;
Ikuo Ogoh, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A silicon oxide film and a BPSG film are formed on a silicon substrate to serve as insulating films, and a contact hole is selectively formed in the insulating films. An impurity diffusion layer is formed on the surface layer of the semiconductor substrate at the bottom portion of the contact hole. A second metal film serving as a metal electrode is formed to cover the BPSG film and the impurity diffusion layer, and a first metal film serving as a barrier layer is formed between the second metal film and the BPSG film and impurity diffusion layer. The first metal film prevents boron contained in the BPSG film from being diffused in the second metal film, thereby to prevent precipitation of silicon in the contact hole.