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. 08, 2002
Filed:
Sep. 07, 2000
Tsuyoshi Uematsu, Kodaira, JP;
Yoshiaki Yazawa, Hoya, JP;
Hiroyuki Ohtsuka, Annaka, JP;
Ken Tsutsui, Hinode, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To form an impurity diffusion layer on only one side of a semiconductor substrate at least one semiconductor substrate and at least one diffusion protecting plate are put close to each other and a first impurity diffusion is perfomed on them, or at least one semiconductor substrate and at least one diffusion protecting plate are put close to each other and a first impurity diffusion is performed on them and then the semiconductor substrate and the diffusion protecting plate are arranged such that those sides on which the impurity diffusion has been performed face each other and a second impurity diffusion is performed. The diffusion protecting plate may be replaced by a semiconductor substrate. The first and second impurity diffusions may be performed using an impurity of the same conductivity type.