Pixel with spatially varying sensor positions

• US 7,432,491 B2
• Filed: 10/24/2005
• Issued: 10/07/2008
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Micron Technology, Inc.
• Inventors: Gazeley, William G., Silsby, Christopher D., Borg, Matthew M.
• Primary Examiner(s): Epps; Georgia Y.
• Assistant Examiner(s): Ko; Tony
• Application Number:
  US11/256,743
• Publication Number:
  US 20060249654A1
• Time in Patent Office: 1,079 Days
• Field of Search: 250/208.1, 257/184, 257/187, 257291-293, 257/203, 257/221, 257/462, 257/929
• US Class Current: 250/208.1
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• 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 27/14623 Optical shielding
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14632 Wafer-level processed structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14689 MOS based technologies

Abstract

An image sensor including a substrate, at least one metal layer, and a plurality of pixels arranged in array. Each pixel includes a sense element disposed in the substrate and at least one metal interconnect segment disposed in the at least one metal layer. The array includes a pair of perpendicular axes extending from an optical center, wherein for a line of pixels extending perpendicularly from one of the axes to a peripheral edge of the array a spacing between the sense elements of consecutive pairs of pixels of the line is at least equal to a spacing between the associated at least one metal interconnect segments, and wherein for at least one consecutive pair of pixels of the line the spacing between the sense elements is greater by an incremental amount than the spacing between the corresponding at least one metal interconnect segments.

Claims

1. An image sensor comprising:

a substrate;

at least a first metal layer, disposed over the substrate; and

a plurality of pixels arranged in an array having a pair of perpendicular axes extending from an optical center, each pixel including a sense element disposed at least partially in the substrate and at least an associated first metal interconnect segment disposed in the first metal layer,

wherein for a line of consecutive pixels extending substantially perpendicularly from one of the axes to a peripheral edge of the array, (i) a pitch between corresponding ones of the associated first metal interconnect segments of each consecutive pair of pixels of the line is equal to a first distance, (ii) a pitch between sense elements of each consecutive pair of pixels of the line is at least equal to the first distance, and (iii) a pitch between each consecutive pair of pixels of the line is equal to a second distance which is greater than the first distance.

2. The image sensor of claim 1, wherein the pitch between the sense elements of each consecutive pair of pixels of the line is based on a predetermined distance of a respective consecutive pair of pixels from the optical center.

3. The image sensor of claim 1, wherein the pitch between the sense elements of each consecutive pair of pixels is based on a predetermined angle of incidence of light incident upon a surface of the array.

4. The image sensor of claim 1, wherein the pitch between the sense elements of each consecutive pair of pixels of the line is equal to the second distance.

5. The image sensor of claim 1, wherein the pitch between consecutive sense elements for a portion of the sense elements of the array is greater than the first distance such that each sense element of the line of pixels substantially aligns with a design grid associated with the image sensor.

6. The image sensor of claim 1, further comprising a second metal layer, wherein:

the first metal layer is positioned between the substrate and the second metal layer, wherein each pixel includes at least an associated second metal interconnect segment disposed in the second metal layer,

a pitch between corresponding ones of the associated second metal interconnect segments of each consecutive pair of pixels of the line is at most equal to the first distance, and

a pitch between corresponding ones of the second metal interconnect segments of each consecutive pair of pixels of the line is equal to a third distance which is less than the first distance.

7. The image sensor of claim 6, wherein the pitch between the associated second metal interconnect segments of consecutive pairs of pixels is based on a predetermined distance of the consecutive pairs of pixels from the optical center.

8. The image sensor of claim 6, wherein the pitch between the associated second metal interconnect segments of consecutive pairs of pixels is based on a predetermined angle of incidence of light incident upon a surface of the array.

9. The image sensor of claim 1, wherein the line of pixels comprises at least a portion of a row of pixels of the array.

10. The image sensor of claim 1, wherein the line of pixels comprises at least a portion of a column of pixels of the array.

11. The image sensor of claim 1, wherein the image sensor comprises a complimentary metal oxide type image sensor.

12. A method of configuring an image sensor including a substrate, a first metal layer, and an array of pixels having a pair of perpendicular axes extending from an optical center, each pixel including a sense element disposed at least partially within the substrate and at least an associated first metal interconnect segment disposed in the first metal layer, the method comprising:

positioning corresponding ones of the associated first metal interconnect segments of each consecutive pair of pixels of a line of pixels extending substantially perpendicularly from one of the axes to a peripheral edge of the array at a pitch equal to a first distance;

positioning the sense elements of each consecutive pair of pixels of the line at a pitch at least equal to the first distance; and

positioning each consecutive pair of pixels of the line at a pitch equal to a second distance which is greater than the first distance.

13. The method of claim 12, wherein the positioning of the sense elements of each consecutive pair of pixels of the line at a pitch at least equal to the first distance includes positioning the sense elements of each consecutive pair of pixels of the line at a pitch equal to the second distance.

14. The method of claim 12, wherein the positioning of the sense elements of each consecutive pair of pixels is based on a distance of a respective consecutive pair of pixels from the optical center.

15. The method of claim 12, wherein the positioning of the sense elements of consecutive pairs of pixels of the line includes positioning the sense elements of a portion of the consecutive pairs of sense elements at a pitch greater than the first distance such that each of the sense elements of the line of pixels aligns with a design grid associated with the image sensor.

16. An image sensor comprising:

a substrate;

at least a first metal layer disposed over the substrate; and

an array of pixels having an optical center, each pixel having a sense element disposed in the substrate and associated first and second metal interconnect segments disposed in the first metal layer, wherein each of the first metal interconnect segments have a first pitch, wherein the sense elements have a plurality of pitches which are at least equal to the first pitch and, for selected pixels of the array, have pitches that are greater than the first pitch such that an offset value equal to a distance of the sense element from the optical center minus a distance of the associated first metal interconnect segment from the optical center is greater for a first pixel proximate to a peripheral edge of the array than for a second pixel proximate to the optical center.

17. The image sensor of claim 16, wherein a portion of the sense elements have a second pitch which is greater than the first pitch such that the offset value of a pixel increases with an increasing distance of the pixel from the optical center.

18. The image sensor of claim 16, wherein each of the sense elements of each of the pixels includes a photodetector, the photodetector of the first pixel proximate the peripheral edge is greater in dimension than the photodetector of the second pixel proximate the optical center by an amount up to a difference between the offset values associated with the first and second pixels.

19. The image sensor of claim 16, wherein the pitches between the sense elements are such that the sense elements substantially align with a design grid associated with the image sensor.

20. The image sensor of claim 16, wherein the first and second pixels are substantially along a line extending from the optical center to the peripheral edge of the array, wherein the offset value of the first pixel is greater than the offset value of the second pixel when the line extends from the optical center in a first direction and the offset value of the first pixel is greater than the offset value of second pixel when the line extends from the optical center in a second direction which is opposite the first direction.