Pumps for CMOS imagers

• US 8,183,515 B2
• Filed: 03/18/2010
• Issued: 05/22/2012
• Est. Priority Date: 06/16/2003
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Rhodes, Howard E.
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): WILLIAMS, DON J
• Application Number:
  US12/727,036
• Publication Number:
  US 20100258709A1
• Time in Patent Office: 796 Days
• Field of Search: 250/208.1, 250/214.1, 250/214.R, 250/214.C, 250/214.LA, 250/214.A, 250/214.LS, 250/214.AG, 250/214.AL, 250/214.SW, 250/216, 257/231, 257/236, 257/239, 257/204, 257/207, 257/208, 257225-229, 257257-258, 257290-291, 257/299, 348/294, 348/297, 348298-302, 348307-311, 348/241, 327/536
• US Class Current: 250/214.R
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14656 Overflow drain structures
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• 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 3/1568 for disturbance correction or prevention within the image-sensor, e.g. biasing, blooming, smearing correction circuits H04N25/62

Abstract

A pixel for an imaging device is described. The pixel includes a photosensitive device provided within a substrate for providing photo-generated charges, a circuit associated with the photosensitive device for providing at least one pixel output signal representative of the photo-generated charges, the circuit includes at least one operative device that is responsive to a first control signal during operation of the associated circuit and a pump circuit. The pump circuit may include substrate pumps, charge pumps and/or voltage pumps. The pixel may also be embedded in an imaging system.

Claims

1. A method of operating a pixel cell of an imaging device, said method comprising:

receiving an external supply voltage;

applying a first pumped voltage based on the received external supply voltage to a first gate to store photo-generated charges at a storage node;

applying a second pumped voltage based on the received external supply voltage to a second gate to produce a pixel output signal from the stored photo-generated charges; and

applying a third pumped voltage based on the received external supply voltage to a portion of the pixel cell to operate as an operating voltage of the pixel cell.

2. The method of claim 1, wherein the first and second pumped voltages are respectively generated using first and second pump circuits connected to the external supply voltage.

3. The method of claim 1, wherein one of the first or second pumped voltages is regulated to a voltage less than the external supply voltage.

4. The method of claim 1, wherein one of the first or second pumped voltages is negative, being less than a ground reference voltage.

5. The method of claim 1, wherein the first gate is part of an n-channel device and the first pumped voltage is applied to an n+ diffusion region of the n-channel device.

6. The method of claim 1, wherein the second gate is part of an n-channel device and the second pumped voltage is applied to an n+ diffusion region of the n-channel device.

7. The method of claim 1, wherein the first gate is part of a p-channel device and the first pumped voltage is applied to a p+ diffusion region of the p-channel device.

8. The method of claim 1, wherein the second gate is part of a p-channel device and the second pumped voltage is applied to a p+ diffusion region of the p-channel device.

9. The method of claim 1, further comprising applying a fourth pumped voltage based on the received external supply voltage to a third gate to reset the storage node.

10. The method of claim 1, further comprising generating a pumped supply voltage from a negative substrate pump.

11. The method of claim 1, further comprising generating a pumped supply voltage from a positive substrate pump.

12. A method of operating a pixel cell of an imaging device, said method comprising:

generating a pumped supply voltage from a substrate pump;

applying the pumped supply voltage to a portion of the pixel cell to operate as an operating voltage of the pixel cell;

applying a first pumped control voltage to a first gate to store photo-generated charges at a storage node;

applying a second pumped control voltage to a second gate to produce a pixel output signal from the stored photo-generated charges; and

applying a third pumped control voltage to a third gate to reset the storage node.

13. The method of claim 12, wherein the first, second and third pumped control voltages are respectively generated using first, second and third pump circuits connected to an external supply voltage.

14. The method of claim 12, wherein one of the first, second or third pumped control voltages is regulated to a voltage less than an external supply voltage.

15. The method of claim 12, wherein one of the first, second or third pumped control voltages is negative, being less than a ground reference voltage.

16. The method of claim 12, wherein the first gate is part of an n-channel device and the first pumped control voltage is applied to an n+ diffusion region of the n-channel device.

17. The method of claim 12, wherein the second gate is part of an n-channel device and the second pumped control voltage is applied to an n+ diffusion region of the n-channel device.

18. The method of claim 12, wherein the third gate is part of an n-channel device and the third pumped control voltage is applied to an n+diffusion region of the n-channel device.

19. The method of claim 12, wherein the first gate is part of a p-channel device and the first pumped control voltage is applied to a p+ diffusion region of the p-channel device.

20. The method of claim 12, wherein the second gate is part of a p-channel device and the second pumped control voltage is applied to a p+ diffusion region of the p-channel device.

21. The method of claim 12, wherein the third gate is part of a p-channel device and the third pumped control voltage is applied to a p+ diffusion region of the p-channel device.

22. The method of claim 12, wherein the pumped supply voltage is generated from a negative substrate pump.

23. The method of claim 12, wherein the pumped supply voltage is generated from a positive substrate pump.

24. A method of operating a pixel cell of an imaging device, said method comprising:

receiving an external supply voltage;

applying a first pumped voltage based on the received external supply voltage to a first gate to reset a storage node;

applying a second pumped voltage based on the received external supply voltage to a second gate to transfer photo-generated charges to the storage node; and

applying a third pumped voltage based on the received external supply voltage to a portion of the pixel cell to operate as an operating voltage of the pixel cell.

25. The method of claim 24, further comprising:

applying a fourth pumped voltage based on the received external supply voltage to a third gate to produce a pixel output signal from the stored photo-generated charges.

26. The method of claim 24, further comprising:

applying a fourth pumped voltage based on the received external supply voltage to a third gate to drain away excess photo-generated charges.