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:
Jun. 08, 2004
Filed:
Apr. 02, 2003
Toshiaki Kirihata, Poughkeepsie, NY (US);
Subramanian S. Iyer, Mount Kisco, NY (US);
John W. Golz, Garrison, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Gain cells adapted to trench capacitor technology and memory array configured with these gain cells are described. The 3T and 2T gain cells of the present invention include a trench capacitor attached to a storage node such that the storage voltage is maintained for a long retention time. The gate of the gain transistor and the trench capacitor are placed alongside the read and write wordline. This arrangement makes it possible to have the gain transistor directly coupled to the trench capacitor, resulting in a smaller cell size. The memory cell includes a first transistor provided with a gate, a source, and a drain respectively coupled to a read wordline, a first node, and a read bitline; a second transistor having a gate, a source, and a drain respectively coupled to a storage node, to a voltage source, and to the first node; a third transistor having a gate, a source, and a drain respectively coupled to a write wordline, the storage node, and a write bitline; and a capacitor having a first terminal connected to the storage node and a second terminal connected to a voltage source.