Solid state imaging element having horizontal scanning circuit for providing reset signals

• US 8,031,248 B2
• Filed: 09/20/2004
• Issued: 10/04/2011
• Est. Priority Date: 06/08/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yonemoto, Kazuya, Suzuki, Ryoji, Ueno, Takahisa, Shiono, Koichi
• Primary Examiner(s): WHIPKEY, JASON T
• Application Number:
  US10/944,977
• Publication Number:
  US 20050041127A1
• Time in Patent Office: 2,570 Days
• Field of Search: 348/302, 348/308, 348/294, 257/292, 257/291, 250/208.1
• US Class Current: 348/308
• 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 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14638 Structures specially adapted for transferring the charges across the imager perpendicular to the imaging plane
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 25/441 by reading contiguous pixels from selected rows or columns of the array, e.g. interlaced scanning
• CPC Class Codes: H04N 25/65 applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS
• CPC Class Codes: H04N 25/767 Horizontal readout lines, multiplexers or registers
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself
• CPC Class Codes: H04N 3/1512 for MOS image-sensors, e.g. MOS-CCD H04N3/1581 takes precedence
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

Since the great number of elements constituting a unit pixel having an amplification function would hinder reduction of pixel size, unit pixel n,m arranged in a matrix form is comprised of a photodiode, a transfer switch for transferring charges stored in the photodiode, a floating diffusion for storing charges transferred by the transfer switch, a reset switch for resetting the floating diffusion, and an amplifying transistor for outputting a signal in accordance with the potential of the floating diffusion to a vertical signal line, and by affording vertical selection pulse φVn to the drain of the reset switch to control a reset potential thereof, pixels are selected in units of rows.

Claims

1. A solid-state imaging element comprising:

a transfer switch having a drain, said drain for the transfer switch being a photodiode;

a transfer selection switch having a source of a first conductivity type, said source for the transfer selection switch being electrically connected to a gate for the transfer switch,

wherein said photodiode includes a first region of said first conductivity type and a second region of a second conductivity type, said second region being between said source for the transfer selection switch and said first region.

2. A solid-state imaging element as claimed in claim 1, wherein said first and second regions are between a hole store layer and a substrate, said hole store layer being of said second conductivity type.

3. A solid-state imaging element as claimed in claim 2, wherein said substrate includes a well of said second conductivity type, said first and second regions being between said hole store layer and said well.

4. A solid-state imaging element as claimed in claim 1, wherein said source for the transfer selection switch physically contacts said photodiode.

5. A solid-state imaging element as claimed in claim 1, wherein said second conductivity type is opposite to said first conductivity type.

6. A solid-state imaging element as claimed in claim 1, wherein a floating diffusion is a source for said transfer switch and a source for a reset switch, said floating diffusion being of said first conductivity type.

7. A solid-state imaging element as claimed in claim 6, wherein a gate for said reset switch is electrically connected to a reset line.

8. A solid-state imaging element as claimed in claim 6, wherein a drain for the reset switch is electrically connected to a vertical selection line.

9. A solid-state imaging element as claimed in claim 6, wherein said reset switch has a drain of the first conductivity type, said drain for the reset switch being electrically connected to a gate of said transfer selection switch.

10. A solid-state imaging element as claimed in claim 9, wherein a source for an amplifying switch is of said first conductivity type, another second region of said second conductivity type being between said source for the amplifying switch and a drain for the reset switch.

11. A solid-state imaging element as claimed in claim 10, wherein said another second region physically contacts said source for the amplifying switch and said drain for the reset switch.

12. A solid-state imaging element as claimed in claim 10, wherein said floating diffusion is electrically connected to a gate for said amplifying switch, a drain for said amplifying switch being electrically connected to a pixel power source.

13. A solid-state imaging element as claimed in claim 10, wherein a source for said amplifying switch is electrically connected to a vertical signal line, said a source for said amplifying switch being of said first conductivity type.

14. A solid-state imaging element as claimed in claim 1, wherein a drain for said transfer selection switch is electrically connected to a transfer line.