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. 18, 1994
Filed:
Mar. 12, 1993
Tsukasa Ohoka, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A method of manufacturing a semiconductor device includes the following steps. A wide groove portion is formed in a predetermined portion of one major surface of a first semiconductor substrate. A first insulating film is formed on the bottom surface of the groove portion. The major surface of the first semiconductor substrate except for the first insulating film is polished to form a mirror-polished surface on the same level as the surface of the first insulating film. One major surface of a second semiconductor substrate is bonded to the mirror-polished surface of the first semiconductor substrate and the surface of the first insulating film by direct bonding, and the resultant structure is heat-treated, thereby forming a composite semiconductor substrate. A groove having a ring-like planar shape is formed to extend from the other major surface of the first semiconductor substrate constituting the composite semiconductor substrate to the first insulating film. A second insulating film is formed on the side walls of the ring-like groove. An island-like element formation region insulated/isolated from the remaining region by the first and second insulating films is formed on the first semiconductor substrate.