Optical sensor element, imaging device, electronic equipment and memory element

• US 8,194,469 B2
• Filed: 01/28/2009
• Issued: 06/05/2012
• Est. Priority Date: 01/31/2008
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tanaka, Tsutomu, Gosain, Dharam Pal
• Primary Examiner(s): Luu, Pho M
• Application Number:
  US12/361,049
• Publication Number:
  US 20100097838A1
• Time in Patent Office: 1,224 Days
• Field of Search: 365/185.3, 365/185.14, 365/185.18, 365/185.24, 365/112
• US Class Current: 365/185.3
• CPC Class Codes: G11C 13/047 using electro-optical elements G11C13/042 takes precedence
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

An optical sensor element has a gate electrode opposed to a semiconductor layer made of an oxide semiconductor via a gate insulating film, source and drain electrodes being connected to the semiconductor layer, wherein the amount of light received by the semiconductor layer is read out as a drain current which changes in a non-volatile manner relative to a gate voltage.

Claims

1. An optical sensor element having a gate electrode opposed to a semiconductor layer made of an oxide semiconductor via a gate insulating film, source and drain electrodes being connected to the semiconductor layer, wherein

the amount of light received by the semiconductor layer is read out as a drain current which changes in a non-volatile manner relative to a gate voltage, wherein

a reset operation is performed before the light reception of the semiconductor layer to restore the drain current relative to the gate voltage to the initial state before the light reception of the semiconductor layer.

2. The optical sensor element of claim 1, wherein

the drain current is read out when the gate voltage is equal to or lower than the threshold voltage in an initial state before the light reception of the semiconductor layer and equal to or higher than the voltage during the light reception of the semiconductor layer.

3. The optical sensor element of claim 1, wherein

as the reset operation, a positive voltage is applied to the gate electrode with the source and drain electrodes shorted together, or the semiconductor layer is heated.

4. The optical sensor element of claim 3, wherein

the heating is conducted by passing a current between the source and drain electrodes.

5. An imaging device having an optical sensor element, the optical sensor element having a gate electrode opposed to a semiconductor layer made of an oxide semiconductor via a gate insulating film, source and drain electrodes being connected to the semiconductor layer, wherein

the amount of light received by the semiconductor layer is read out as a drain current which changes in a non-volatile manner relative to a gate voltage, wherein

a reset operation is performed before the light reception of the semiconductor layer to restore the drain current relative to the gate voltage to the initial state before the light reception of the semiconductor layer.

6. The imaging device of claim 5, wherein

the drain current is read out when the gate voltage is equal to or lower than the threshold voltage in an initial state before the light reception of the semiconductor layer and equal to or higher than the voltage during the light reception of the semiconductor layer.

7. The imaging device of claim 5, wherein

as the reset operation, a positive voltage is applied to the gate electrode with the source and drain electrodes shorted together, or the semiconductor layer is heated.

8. The imaging device of claim 7, wherein

the heating is conducted by passing a current between the source and drain electrodes.

9. Electronic equipment having an optical sensor element, the optical sensor element having a gate electrode opposed to a semiconductor layer made of an oxide semiconductor via a gate insulating film, source and drain electrodes being connected to the semiconductor layer, wherein

the amount of light received by the semiconductor layer is read out as a drain current which changes in a non-volatile manner relative to a gate voltage, wherein

a reset operation is performed before the light reception of the semiconductor layer to restore the drain current relative to the gate voltage to the initial state before the light reception of the semiconductor layer.

10. The electronic equipment of claim 9, wherein

the drain current is read out when the gate voltage is equal to or lower than the threshold voltage in an initial state before the light reception of the semiconductor layer and equal to or higher than the voltage during the light reception of the semiconductor layer.

11. The electronic equipment of claim 9, wherein

as the reset operation, a positive voltage is applied to the gate electrode with the source and drain electrodes shorted together, or the semiconductor layer is heated.

12. The electronic equipment of claim 11, wherein

the heating is conducted by passing a current between the source and drain electrodes.