IP Library › Granted Patent US 7,982,220
Granted Patent B2
US 7,982,220 · App. 12/834,057 · Granted Jul 19, 2011

Display device, method for manufacturing the same, and electronic device having the same

Assignee: Semiconductor Energy Laboratory Co., Ltd.
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Quick Facts
Patent No.
US 7,982,220
App. No.
12/834,057
Granted
Jul 19, 2011
Kind
B2
Abstract

In a case where a p-channel thin film transistor is used as a thin film transistor that is electrically connected to a light-emitting element and drives the light-emitting element, a value of cutoff current of the p-channel thin film transistor is made lower than that of a p-channel thin film transistor of a driver circuit. Specifically, channel doping is selectively performed on a semiconductor layer of a thin film transistor included in a pixel.

Claims (11)

1. A display device comprising:

a pixel comprising a first p-channel thin film transistor and a light-emitting element; and

a driver circuit comprising a second p-channel thin film transistor,

wherein one of a source and a drain of the first p-channel thin film transistor is electrically connected to the light-emitting element,

wherein a concentration of an impurity element imparting p-type conductivity included in a channel region of the first p-channel thin film transistor is lower than a concentration of an impurity element imparting p-type conductivity included in a channel region of the second p-channel thin film transistor.

2. The display device according to claim 1 ,

wherein a value of cutoff current of the first p-channel thin film transistor is less than or equal to 2×10 −11 A.

3. The display device according to claim 1 ,

wherein the impurity element imparting p-type conductivity is boron.

4. An electronic device having the display device according to claim 1 ,

wherein the electronic device is selected from the group consisting of a portable information terminal device, a digital video camera, a mobile phone, a portable television device, a portable computer, and a television device.

Priority Claims (1)
JP 2006-179165 · Jun 29, 2006 · national
Continuity (2)
Division 11819154 · Jun 25, 2007
Related Publication 20100276694A1 · Nov 4, 2010