Image sensor and electronic camera

• US 10,455,173 B2
• Filed: 09/27/2016
• Issued: 10/22/2019
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Saruwatari, Osamu
• Primary Examiner(s): Camargo, Marly S
• Application Number:
  US15/763,137
• Publication Number:
  US 20180278873A1
• Time in Patent Office: 1,120 Days
• Field of Search: 348308, 348294-304, 257291, 257292, 257443, 257226, 257257, 257462, 438 57, 438 67, 438 90, 438107
• CPC Class Codes: H01L 27/14 including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation radiation-sensitive components structurally associated with one or more electric light sources only H01L31/14; couplings of light guides with optoelectronic elements G02B6/42
• CPC Class Codes: H01L 27/146 Imager structures
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14634 Assemblies, i.e. Hybrid structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H04N 25/58 involving two or more exposures
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/709 Circuitry for control of the power supply
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

An image sensor includes a first voltage source that supplies a first voltage and a plurality of pixels supplied with the first voltage. The pixel includes a photoelectric conversion unit that photoelectrically converts incident light, an accumulation unit to which an electric charge resulting from photoelectric conversion by the photoelectric conversion unit is transferred and accumulated, a transfer unit that transfers the electric charge from the photoelectric conversion unit to the accumulation unit; a second voltage source that supplies a second voltage, and a supply unit that supplies the transfer unit with a transfer signal based on either the first voltage supplied by the first voltage source or the second voltage supplied by the second voltage source.

Claims

1. An image sensor, comprising

a first voltage source that supplies a first voltage and

a plurality of pixels supplied with the first voltage, wherein

the pixels each include:

a photoelectric conversion unit that photoelectrically converts incident light;

an accumulation unit to which an electric charge resulting from photoelectric conversion by the photoelectric conversion unit is transferred and accumulated;

a transfer unit that transfers the electric charge from the photoelectric conversion unit to the accumulation unit;

a second voltage source that supplies a second voltage; and

a supply unit that supplies the transfer unit with a transfer signal based on either the first voltage supplied by the first voltage source or the second voltage supplied by the second voltage source; and

the supply unit includes a capacitor arranged between the first voltage source and the transfer unit, and a second resistor arranged between the second voltage source and the transfer unit.

2. The image sensor according to claim 1, wherein:

the supply unit includes a first resistor arranged between the first voltage source and the transfer unit and a second resistor arranged between the second voltage source and the transfer unit.

3. The image sensor according to claim 2, comprising:

a first semiconductor substrate provided with the plurality of pixels; and

a second semiconductor substrate provided with an A/D conversion unit for each of the plurality of pixels, the A/D conversion unit outputting a digital signal depending on the amount of the electric charge accumulated in the accumulation unit, wherein;

the first voltage source is provided on the second semiconductor substrate; and

the first resistor includes at least an electrode connecting the first semiconductor substrate and the second semiconductor substrate.

4. The image sensor according to claim 1, wherein:

a substrate voltage is applied to the image sensor;

the first voltage source supplies a voltage lower than the substrate voltage; and

the second voltage source supplies a voltage higher than the substrate voltage.

5. The image sensor according to claim 4, wherein:

either a third voltage higher than or equal to the substrate voltage or a fourth voltage higher than or equal to the substrate voltage and higher than the third voltage is inputted to the supply unit; and

the supply unit outputs the transfer signal that is the first voltage if the third voltage is inputted and supplies the transfer signal that is the second voltage if the fourth voltage is inputted.

6. The image sensor according to claim 1, wherein:

the transfer unit electrically connects the photoelectric conversion unit and the accumulation unit to transfer the electric charge generated by the photoelectric conversion unit to the accumulation unit; and

the supply unit supplies the transfer unit with the transfer signal for electrically connecting or disconnecting the photoelectric conversion unit and the accumulation unit.

7. The image sensor according to claim 1, comprising:

a first semiconductor substrate provided with the plurality of pixels; and

a second semiconductor substrate provided with an A/D conversion unit for each of the plurality of pixels, the A/D conversion unit outputting a digital signal depending on the amount of the electric charge accumulated in the accumulation unit.

8. The image sensor according to claim 1, wherein:

a part of a plurality of supply units each corresponds to the supply unit transfer the electric charge generated by the photoelectric conversion unit during a first period to the accumulation unit and another part of the plurality of supply units transfer the electric charge generated by the photoelectric conversion unit during a second period to the accumulation unit, the second period having a length different from that of the first period.

9. The image sensor according to claim 1, wherein:

the photoelectric conversion unit is a pinned photodiode; and

the transfer unit transfers the electric charge resulting from photoelectric conversion by the photoelectric conversion unit to the accumulation unit if the transfer signal is the first voltage based on a voltage supplied by the first voltage source, and does not transfer the electric charge resulting from photoelectric conversion by the photoelectric conversion unit to the accumulation unit if the transfer signal is the second voltage based on a voltage supplied by the first voltage source.

10. The image sensor according to claim 1, wherein:

each of the plurality of pixels has a switching unit that electrically connect or disconnect the supply unit and the first voltage source.

11. An electronic camera comprising the image sensor according to claim 1.