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. 17, 1993
Filed:
Apr. 30, 1990
Yuuichi Mikata, Kawasaki, JP;
Katsunori Ishihara, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A poly-Si film is formed on a first insulating film overlying a semiconductor substrate. A second insulating film is formed on the poly-Si film. The poly-Si film comprises a layered structure of a non-single crystal type silicon film and contains a phosphorus concentration of less than 5.times.10.sup.20 cm.sup.-3 or contains no phosphor, a poly-Si film having a phosphorus concentration of over 5.times.10.sup.20 cm.sup.-3 and a poly-Si film having a phosphorus concentration of less than 5.times.10.sup.20 cm.sup.-3 or containing no phosphorus. Since the phosphorus concentrations of the non-single crystal type silicon film adjacent to the first insulating film and poly-Si film adjacent to the second insulating film are reduced, the phosphorus in these two films are not diffused toward the corresponding insulating films. It is thus possible to improve the breakdown voltage across the first and second insulating films.