Pixel with spatially varying metal route positions

• US 7,214,920 B2
• Filed: 05/06/2005
• Issued: 05/08/2007
• 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.
• Primary Examiner(s): Luu; Thanh X.
• Assistant Examiner(s): Ko; Tony
• Application Number:
  US11/123,782
• Publication Number:
  US 20060249653A1
• Time in Patent Office: 732 Days
• Field of Search: 257/184, 257/431, 257/443, 257290-292, 250/208.1, 250/214.1, 348/294
• 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 27/14636 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 an array of pixels having an optical center, the array including a first pixel substantially at a first distance from the optical center in a first direction and a second pixel substantially at the first distance from the optical center in a second direction which is opposite the first direction. The first pixel includes a first metal segment and a first interlayer connect element. The first metal segment is positioned in a second metal layer at a shift distance toward the optical center from a first position. The first interlayer connect element is coupled between the first metal segment and a first metal layer and is positioned at the shift distance toward the optical center from a second position, wherein the second position is coincident with the first position. The second pixel includes a second metal segment, a second interlayer connect element, and a span element. The second metal segment is positioned in the second metal layer at the shift distance toward the optical center from a third position. The second interlayer connect element is coupled between the first and second metal layers, the interlayer connect element positioned at a fourth position which is coincident with the third position. The span element coupled to and extending from the second metal segment in generally the second direction and coupled to the second interlayer connect element.

Claims

1. An image sensor including an array of pixels having an optical center, the array comprising:

a first pixel substantially at a first distance from the optical center in a first direction including;

a first metal segment positioned in a second metal layer at a shift distance toward the optical center from a first position; and

a first interlayer connect element coupled between the first metal segment and a first metal layer, the interlayer connect element positioned at the shift distance toward the optical center from a second position, wherein the second position is coincident with the first position; and

a second pixel substantially at the first distance from the optical center in a second direction which is opposite the first direction including;

a second metal segment positioned in the second metal layer at the shift distance toward the optical center from a third position;

a second interlayer connect element coupled between the first and second metal layers, the interlayer connect element positioned at a fourth position which is coincident with the third position; and

a span element coupled to and extending from the second metal segment in generally the second direction and coupled to the second interlayer connect element.

2. The image sensor of claim 1, wherein a magnitude of the shift distance increases non-linearly across the image sensor with distance from the optical center.

3. The image sensor of claim 1, where a direction of the shift distance on an orientation the pixel relative to the optical center.

4. The image sensor of claim 1, wherein the shift distance is based on a principal ray angle of light incident upon the first and second pixels.

5. The image sensor of claim 1, wherein the span element is positioned in the second metal layer.

6. The image sensor of claim 1, wherein the span element extends in generally the second direction by at least the shift distance.

7. The image sensor of claim 1, wherein the span element is contiguous with and extends from the second metal segment.

8. The image sensor of claim 1, wherein the first and second metal segment each comprise a voltage bus.

9. The image sensor of claim 1, wherein the first and second metal segments comprise signal buses extending across the array.

10. The image sensor of claim 1, wherein the image sensor comprises a complimentary metal-oxide semiconductor imaging sensor.

11. The image sensor of claim 1, wherein each of the pixels of the array comprises a buried-gate photodiode type pixel.

12. The image sensor of claim 1, wherein the first metal layer is positioned between the second metal layer and a silicon substrate.

13. A method of configuring an image sensor including an array of pixels having an optical center and having a first pixel substantially at a first distance from the optical center and in a first direction, and second pixel substantially at the first distance from the optical center and in a second direction which is opposite the first direction, the method comprising:

positioning a first metal segment of the first pixel in a second metal layer and at a shift distance toward the optical center from the first position;

positioning a first interlayer connect element, which is coupled between the first metal segment and a first metal layer, at the shift distance toward the optical center from a second position, wherein the second position is substantially coincident with the first position;

positioning a second metal segment of the second pixel in the second metal layer and at the shift distance toward the optical center from a third position;

positioning a second interlayer connect element, which is coupled between the first and second metal layers, at a fourth position which is substantially coincident with the third position; and

positioning a span element in generally the second direction from the second metal segment to the second interlayer connect element to couple the second metal segment to the second interlayer connect element.

14. The method of claim 13, wherein positioning the span element includes providing an extending the span element in the second metal layer.

15. The method of claim 13, wherein positioning the span element includes extending the span element by at least the shift distance.

16. The method of claim 13, wherein the first, second, third, and fourth positions are positions of a base pixel configuration.