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. 10, 1999
Filed:
Feb. 25, 1997
Ikue Kawashima, Kobe, JP;
Ricoh Company, Ltd., Tokyo, JP;
Ricoh Research Institute of General Electronics Co., Ltd., Miyagi, JP;
Abstract
A conductive material is buried into a hole portion of a layer insulating film. A contact portion of the buried conductive material coming in contact with an upper wiring is formed in a convex or concave shape. Materials of the buried conductive material and the upper wiring are selected such that these materials are different from each other. When an upper face of an opening portion of the buried conductive material in a hole portion is formed in a conical shape and .alpha. is set to an angle formed between a surface of the insulating film and a conical slanting face of the upper face of the buried conductive material, a contact area between the buried conductive material and an upper wiring member is equal to 1/cos.alpha. times a contact area between the buried conductive material and the upper wiring member provided in a case in which the upper face of the buried conductive material is formed in the shape of a flat face. In this structure, no contact area between the buried conductive material and the upper wiring member is greatly reduced even when a shift in position between the hole and the upper wiring member is caused.