Photodiode architectures and image capture methods having a plurality of photodiode with a shared electrode

• US 9,595,558 B2
• Filed: 11/12/2014
• Issued: 03/14/2017
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: Owl Autonomous Imaging, Inc.
• Original Assignee: Intrinsix Corp. (CEVA Incorporated)
• Inventors: Petilli, Eugene M.
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US14/539,607
• Publication Number:
  US 20150129747A1
• Time in Patent Office: 853 Days
• Field of Search: 250/214.R, 250/208.1, 250/214.1, 250/551, 257/53, 257/59, 257/428, 257/443, 327/514, 327/515
• US Class Current: 1/1
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H04N 25/17 Colour separation based on photon absorption depth, e.g. full colour resolution obtained simultaneously at each pixel location

Abstract

A photodiode architecture comprises first, second, and third independent photodiodes, and a shared electrode. The first, second, and third photodiodes are each connected to respective sources of bias voltage and to a common shared electrode, whereby the photodiode architecture comprises at least one of a shared anode and shared cathode photodiode architecture. The photodiode architecture selectively reverse biases the first, second, and third photodiodes so that, during operation, at least one of the first, second and third photodiodes is always operating in a photoconducting mode, to enable capture and storage of charge from any photodiode in the architecture operating in photoconducting mode. Advantageously, the first photodiode can be configured to respond to a first wavelength of light and at least one of the second and third photodiodes can be configured to be responsive to a respective second or third wavelength of light shorter than the first wavelength of light.

Claims

1. A photodiode architecture, comprising:

a first photodiode comprising first and second electrodes, the first electrode being coupled to a shared electrode;

a second photodiode operably connected in series with the first photodiode, the second photodiode being independent of the first photodiode, comprising third and fourth electrodes, the third electrode being coupled to the shared electrode; and

a third photodiode operably connected in series with the first photodiode, the third photodiode being independent of the first photodiode and comprising fifth and sixth electrodes, and the fifth electrode being coupled to the shared electrode;

wherein the shared electrode is in operable communication with the first electrode, third electrode, and fifth electrode;

wherein the shared electrode is configured to operate, respectively, as either a shared anode or a shared cathode for the respective first, second, and third photodiodes, wherein the photodiode architecture comprises at least one of a shared anode photodiode architecture and a shared cathode photodiode architecture; and

wherein the first photodiode, second photodiode, third photodiode and shared electrode are constructed and arranged to selectively reverse bias the first, second, and third photodiodes so that, during operation, at least one of the first, second and third photodiodes is operating in a photoconducting mode, to enable capture and storage of charge from any photodiode in the photodiode architecture that is operating in photoconducting mode.

2. A photodiode architecture, comprising:

a first photodiode comprising first and second electrodes, the first electrode being operably coupled to a shared electrode;

a second photodiode operably connected in series with the first, photodiode, the second photodiode being independent of the first photodiode, comprising third and fourth electrodes, the third electrode being operably coupled to the shared electrode; and

a third photodiode operably connected in series with the first photodiode, the third photodiode being independent of the first photodiode and comprising fifth and sixth electrodes, and the fifth electrode being coupled to the shared electrode;

wherein the shared electrode is configured to operate as either a shared anode or a shared cathode for the respective first, second, and third photodiodes; and

wherein the first photodiode, second photodiode, third photodiode and shared electrode are constructed and arranged so that, during operation, at least one of the first, second and third photodiodes is always operating in a photoconducting mode.

3. The photodiode architecture of claim 2, wherein the photodiode architecture is configured as part of a back-side illumination device.

4. The photodiode architecture of claim 2, wherein the first photodiode is configured to respond to a first wavelength of light and at least one of the second and third photodiodes is configured to be responsive to a respective second or third wavelength of light that is shorter than the first wavelength of light.

5. The photodiode architecture of claim 2, wherein at least one of the first, second, and third photodiodes is configured to be responsive to non-visible light and at least one of the first, second and third photodiodes is configured to be responsive to visible light.

6. The photodiode architecture of claim 2, wherein the second and third photodiodes are each constructed and arranged to be responsive to a respective one of visible red light, visible green light, visible blue light, and visible panchromatic light.

7. The photodiode architecture of claim 2, wherein the first photodiode is constructed and arranged to be responsive to any one of infrared light, near infrared (NIR) light, short-wavelength infrared (SWIR) light, long wavelength infrared (LWIR) light, ultraviolet (UV) light, radio wave light, x-ray wave light, and gamma ray light.

8. The photodiode architecture of claim 2, wherein any two of the first, second, and third photodiodes are responsive to the same type of light.

9. The photodiode architecture of claim 2, further comprising a color filter array (CFA) configured to be in operable communication with the first, second, and third photodiodes.

10. The photodiode architecture of claim 2, wherein the first, second, and third photodiodes are arranged in a stacked configuration.

11. The photodiode architecture of claim 2, wherein the photodiode architecture is implemented as part of at least one of an image capture device and an image fusion system.

12. The photodiode architecture of claim 2, wherein the photodiode architecture is configured as part of a front-side-illumination device.

13. The photodiode architecture of claim 2, wherein, during operation of the photodiode architecture, the shared electrode is configured to selectively reverse bias at least one of the first, second, and third photodiodes.

14. A method for capturing an image, the method comprising:

providing a first photodiode having first and second electrodes;

coupling the first electrode to a shared elect ode;

operably connecting a second photodiode in series with the first photodiode, the second photodiode being independent of the first photodiode and having third and fourth electrodes and the third electrode being coupled to the shared electrode;

operably connecting a third photodiode in series with the first photodiode, the third photodiode being independent of the first photodiode and comprising fifth and sixth electrodes, the fifth electrode being coupled to the shared electrode, wherein the shared electrode is in operable communication with the first, third, and fifth electrodes;

configuring the first photodiode to respond to a first wavelength of light and at least one of the second, and third photodiodes to be responsive to a respective second or third wavelength of light that is shorter than the first wavelength of light;

configuring an electrode node that is in operable communication with the first electrode and the third electrode to be a shared electrode that is configured to operate, respectively, as either a shared anode or a shared cathode for the first, second, and third photodiodes, respectively, wherein the photodiode architecture comprises at least one of a shared anode photodiode architecture and a shared cathode photodiode architecture, wherein the shared electrode node is configured to operate, respectively, as either a shared anode node or a shared cathode node; and

constructing and arranging the first photodiode, second photodiode, third photodiode, and shared electrode so that, during operation, at least one of the first, second, and third photodiodes is always operating in a photoconducting mode, to enable capture and storage of charge from any photodiode in the photodiode architecture that is operating photoconducting mode.

15. The method of claim 14, further comprising configuring at least one of the first, second, and third photodiodes to be responsive to nonvisible light and at least one of the first, second and third photodiodes to be responsive to visible light.

16. The method of claim 14, further comprising constructing and arranging the second and third photodiodes to be responsive to a respective one of visible red light, visible green light, visible blue light, and visible panchromatic light.

17. The method of claim 14, further comprising constructing and arranging the first photodiode to be responsive to any one of infrared light, near infrared (NIR) light, short-wavelength infrared (SWIR) light, long wavelength infrared (LWIR) light, ultraviolet (UV) light, radio wave light, x-ray wave light, and gamma ray light.

18. The method of claim 14, further comprising configuring a color filter array (CFA) to be in operable communication with the first, second, and third photodiodes.

19. The method of claim 14, further comprising configuring a photodiode architecture formed at least by the first, second, and third photodiodes and the shared electrode, to be part of at least one of a front-side-illumination device and a back side illumination device.

20. The method of claim 14, further comprising selectively reverse biasing at least one of the first, second, and third photodiodes to ensure that, during operation, at least one of the first, second, and third photodiodes is operating in a photoconducting mode.