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.

Date of Patent:
Oct. 23, 2018

Filed:

Dec. 28, 2016
Applicant:

Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;

Inventors:

Tomoaki Atsumi, Kanagawa, JP;

Shuhei Nagatsuka, Kanagawa, JP;

Kazuaki Ohshima, Kanagawa, JP;

Assignee:

Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C 11/22 (2006.01); G11C 29/50 (2006.01); G11C 11/4096 (2006.01); H01L 27/108 (2006.01);
U.S. Cl.
CPC ...
G11C 29/50004 (2013.01); G11C 11/4096 (2013.01); G11C 29/50016 (2013.01); H01L 27/108 (2013.01);
Abstract

The semiconductor device includes a bit line, a transistor, a retention node, and a capacitor. The transistor has a function of charging or discharging the retention node. The capacitor has a function of retaining a potential of the retention node. A voltage greater than the sum of a writing voltage and a threshold voltage is applied to a gate of the transistor. When the transistor is turned on, a first potential is supplied to the bit line with a reference potential in a floating state. A voltage less than the sum of the writing voltage and the threshold voltage is applied to the gate of the transistor. When the transistor is turned on, a second potential is supplied to the bit line with a reference potential in a floating state. With use of the first and second potentials, the threshold voltage of the transistor is calculated without being influenced by parasitic capacitance and variations in the storage capacitance of the capacitor.


Find Patent Forward Citations

Loading…