Semiconductor device having a transistor with an oxide semiconductor layer between a first gate electrode and a second gate electrode

Patent metadata

Field	Value
Publication number	US-9524993-B2
Application number	US-201314074034-A
Country	US
Kind code	B2
Filing date	Nov 7, 2013
Priority date	Feb 12, 2010
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A transistor a gate of which, one of a source and a drain of which, and the other are electrically connected to a selection signal line, an output signal line, and a reference signal line, respectively and a photodiode one of an anode and a cathode of which and the other are electrically connected to a reset signal line and a back gate of the transistor, respectively are included. The photodiode is forward biased to initialize the back-gate potential of the transistor, the back-gate potential is changed by current of the inversely-biased photodiode flowing in an inverse direction in accordance with the light intensity, and the transistor is turned on to change the potential of the output signal line, so that a signal in accordance with the intensity is obtained.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a photodiode; and
a transistor comprising:
a first gate electrode;
an oxide semiconductor layer over the first gate electrode; and
a second gate electrode over the oxide semiconductor layer,

wherein one electrode of the photodiode is connected to the second gate electrode of the transistor, and
wherein the other electrode of the photodiode is connected to a reset signal line.

2. The…

Assignees

• Semiconductor Energy Lab

Inventors

• Kurokawa Yoshiyuki

Classifications

• H04N25/77

  Electricity · mapped topic

• G02F1/133512

  Physics · mapped topic

• G02F1/13338

  Physics · mapped topic

• G09G2360/145

  Physics · mapped topic

• G09G2320/0666

  Physics · mapped topic