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:
Sep. 15, 2009
Filed:
Jul. 21, 2006
Applicant:
Natsuki Sato, Tokyo, JP;
Inventor:
Natsuki Sato, Tokyo, JP;
Assignee:
Elpida Memory, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 45/00 (2006.01); H01L 31/032 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a semiconductor device, a phase change layer is formed as a side wall and is therefore reduced in volume. Even if the number of times of rewriting is small, the phase change layer is entirely used as a phase change region. Therefore, the phase change region is not increased in volume even if the number of times of rewriting is increased. Since the volume of the phase change region is not changed, an electric current level required for rewriting is constant. Thus, the semiconductor device having a memory cell capable of carrying out stable rewriting is obtained.