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:
Oct. 26, 2004
Filed:
Jun. 23, 2003
Hideaki Matsuhashi, Saitama, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A lower buried oxide film, a stress-relief film, an upper buried oxide film, and an SOI film are formed over a semiconductor substrate in this order. The thermal expansion coefficient of the stress-relief film is greater than the thermal expansion coefficient of the upper buried oxide film. The stress-relief film desirably has a thermal expansion coefficient equal to or greater than the thermal expansion coefficient of the SOI film. For example, it is formed of a silicon film, or of a composite film laminating a silicon film, a germanium film disposed thereon, and a silicon film disposed thereon. Accordingly, a semiconductor device having an SOI MOSFET is to be provided, which has excellent characteristics such as low parasitic capacitance and a small S value and is hardly affected by the stress generated by the difference between thermal expansion coefficients of the buried oxide film and the SOI film.