Solid state imaging device and driving method thereof

• US 20060028565A1
• Filed: 07/07/2005
• Published: 02/09/2006
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kuwazawa, Kazunobu
• Granted Patent: US 7,583,306 B2
• Time in Patent Office: Days
• US Class Current: 348/294
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof

Abstract

A solid state imaging device, including: a plurality of storage wells which stores an optically generated charge that is generated at a photoelectric conversion region corresponding to an incident light, the plurality of storage wells being inside a substrate; wherein a plurality of the photoelectric conversion regions is arrayed on the substrate in a two dimensional matrix; a plurality of amplifiers each installed per every pair of the photoelectric conversion regions that are adjacent in one direction of the two dimensional matrix, outputting a pixel signal that corresponds to the optically generated charge retained in a floating diffusion region; a plurality of transfer controlling elements, a pair of which is installed in every pair of the photoelectric conversion regions, changing a potential barrier of an optically generated charge transfer route, the transfer route being between each of the storage wells in the pair of the photoelectric conversion regions and the corresponding floating diffusion region, and controlling a transfer of the optically generated charges; wherein each of the plurality of transfer controlling elements has a transfer gate installed on the substrate being separated by an insulation film, and an electric charge retention region being inside the substrate, retaining the optically generated charge under the transfer gate; and wherein each of the plurality of amplifiers is provided with a transistor, a gate of each transistor having a ring-like shape, each of the gates being installed in a manner that at least a part of the gate is sandwiched by portions which are parts cut-off from each pair of the transfer gates, the pair of the transfer gates being adjacent in one direction of the two dimensional matrix.

Claims

1. A solid state imaging device having a pixel array, the pixel array having a plurality of pixels arranged in a matrix, comprising:

a substrate;

a plurality of photoelectric conversion regions formed in the substrate;

a plurality of storage wells formed in the substrate, each of the storage well storing optically generated charges that are generated at each of the photoelectric conversion regions corresponding to an incident light;

a plurality of amplifiers, each of the plurality of amplifiers outputting a pixel signal that corresponds to the optically generated charge retained in a floating diffusion region, each of the plurality of amplifiers shared by two pixels adjacent to each other in a column direction; and

a plurality of transfer controlling elements, each of the plurality of transfer controlling a transfer of the optically generated charges by changing a potential barrier of a transfer route, the transfer route being between the storage well and the floating diffusion region;

wherein each of the plurality of transfer controlling elements including;

a transfer gate formed on the substrate with an insulation film therebetween, and;

an electric charge retention region formed below the transfer gate, the electric charge retention region retaining the optically generated charge;

wherein each of the plurality of amplifiers includes a transistor, a gate of each transistor being a ring-like shape, each of the ring-gates is disposed between two transfer gates adjacent to each other in a column direction.

2. The solid state imaging device according to claim 1, wherein the amplifier is provided with a modulation transistor, having a threshold voltage of a channel being controlled by the electric charge retained in the floating diffusion region, and outputting the pixel signal that corresponds to the electric charge.

3. The solid state imaging device according to claim 1, wherein a diffusion layer that is provided with the transfer route between the floating diffusion region and the electric charge retention region, is installed under another diffusion layer in the substrate.

4. The solid state imaging device according to claim 1, wherein a discharging region for discharging the electric charge being redundant at the storage well is provided.

5. A method for driving a solid state image device, comprising:

wherein the solid state image device includes;

a plurality of storage wells, which stores an optically generated charge that is generated at a photoelectric conversion region corresponding to an incident light, the plurality of storage wells installed per each pixel and being inside a substrate;

wherein a plurality of the photoelectric conversion regions is arrayed on the substrate in a two dimensional matrix;

a plurality of amplifiers each installed per every pair of the photoelectric conversion regions that are adjacent in one direction of the two dimensional matrix, outputting a pixel signal that corresponds to the optically generated charge retained in a floating diffusion region;

a plurality of transfer controlling elements, a pair of which is installed in every pair of the photoelectric conversion regions, changing a potential barrier of an optically generated charge transfer route, the transfer route being between each of the storage wells in the pair of the photoelectric conversion regions and the corresponding floating diffusion region, and controlling a transfer of the optically generated charges;

wherein each of the plurality of transfer controlling elements has a transfer gate installed on the substrate being separated by an insulation film, and a electric charge retention region being inside the substrate, retaining the optically generated charge under the transfer gate; and

the plurality of amplifiers each being a transistor, a gate of each transistor having a ring-like shape, each of the gates being installed in a manner that at least a part of the gate is sandwiched by portions which are parts cut-off from each pair of the transfer gates, the pair of the transfer gates being adjacent in one direction of the two dimensional matrix;

a storing process, for controlling a potential barrier of the transfer route by the transfer controlling element, and storing the optically generated charge to the storage well, while preventing it from flowing to the electric charge retention region in the very least through the transfer route, for the entire pixels at once;

a first transferring process, for controlling the potential barrier of the transfer route by the transfer controlling element, and transferring the optically generated charge stored in the storage well to the electric charge retention region, for the entire pixels at once;

a first read-out process, for controlling voltages of the two transfer gates installed corresponding to the pair of photoelectric conversion region, and reading out a noise component from the transistor, in on direction of the matrix;

a second transfer process, for transferring, in one direction of the matrix, the optically generated charge from one of the two transfer controlling elements in the electric charge retention regions that correspond to the pair of photoelectric conversion regions, to the floating diffusion region;

a second read-out process, for controlling the voltage of the gate installed corresponding to the pair of photoelectric conversion regions, and reading out a signal component from the transistor, based on the transferred optically generated charge.