Vertically integrated photosensor for CMOS imagers

• US 6,927,432 B2
• Filed: 08/13/2003
• Issued: 08/09/2005
• Est. Priority Date: 08/13/2003
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Candelaria, Jon J., Holm, Paige M.
• Primary Examiner(s): Lee, Eddie
• Assistant Examiner(s): VU, QUANG D
• Application Number:
  US10/640,856
• Publication Number:
  US 20050035381A1
• Time in Patent Office: 727 Days
• Field of Search: 257/225, 257/228, 257/257, 257/288, 257/290, 257/291, 257/292, 257/293, 257/294, 438/48, 438/70
• US Class Current: 257/290
• CPC Class Codes: H01L 27/1463 Pixel isolation structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers

Abstract

An exemplary system and method for providing a vertically integrated photosensing element suitably adapted for use in CMOS imaging applications is disclosed as comprising inter alia: a processed CMOS layer (420); and a photosensing element (380) fabricated in a vertically integrated optically active layer (320, 350), where the optically active layer (320, 350) is bonded to the CMOS layer (420) and the optically active layer (320, 350) is positioned near a metalization surface (405) of the CMOS layer (420). Disclosed features and specifications may be variously controlled, configured, adapted or otherwise optionally modified to further improve or otherwise optimize photosensing performance or other material characteristics. Exemplary embodiments of the present invention representatively provide for integrated photosensing components that may be readily incorporated with existing technologies for the improvement of CMOS imaging, device package form factors, weights and/or other manufacturing, device or material performance metrics.

Claims

1. A electronic imaging component, said component comprising:

an electronics layer;

a monocrystalline photosensing element, said photosensing element fabricated in a vertically integrated optically active layer and bonded to said electronics layer;

a substantially vertical interconnect coupled to said electronics layer; and

said monocrystalline photosensing element further comprising a junction surrounding and at least partially encompassing said vertical interconnect, wherein charge carriers may be substantially laterally drawn toward the axis of said vertical interconnect, said junction including one of a p-type and an n-type material having a first side adjacent said vertical interconnect and the other of the one of a p-type and an n-type material adjacent a second side opposed to said first side and positioned horizontally from said first side.

2. The imaging component of claim 1, wherein said electronics layer is substantially fully processed.

3. The imaging component of claim 1, wherein said monocrystalline photosensing element comprises at least one of a photodiode, a photomultiplier, a phototransistor, and a photoconductor.

4. The imaging component of claim 1, wherein said optically active layer comprises at least one of Si, GaAs, InP, GaN, HgCdTe, Ge, SiGe, and SiC.

5. The imaging component of claim 1, wherein said bonding comprises at least one of wafer-to-wafer bonding and die-to-wafer bonding.

6. The imaging component of claim 1, wherein said interconnect comprises:

at least one of a metallized via, an electrical conductor, p-Si, and a semiconductor; and

said interconnect extends substantially through said optically active layer.

7. An electronic imaging component array, said component array comprising:

an electronics array layer;

a monocrystalline photosensing element array, said monocrystalline photosensing element array fabricated in a vertically integrated optically active layer and bonded to said electronics array layer;

a plurality of substantially vertical interconnects coupled to said electronic layer; and

said monocrystalline photosensing element array further comprising a plurality of junctions substantially surrounding and at least partially encompassing said plurality of vertical interconnects, wherein charge carriers may be substantially laterally drawn toward the axes of at least one of said plurality of junctions and said plurality of interconnects, said junctions including one of a p-type and an n-type material having a first side adjacent said vertical interconnect and the other of the one of a p-type and an n-type material adjacent a second side opposed to said first side and positioned horizontally from said first side.

8. The imaging component array of claim 7 having a relatively high interconnect density.

9. The imaging component array of claim 8, wherein said high interconnect density comprises about one connection per up to about 10-250 square microns.

10. The imaging component array of claim 7, wherein said interconnects comprise a plurality of at least one of metallized vias, electrical conductors, p-Si and semiconductors.

11. The imaging component array of claim 7, wherein the photosensing element fill factor is up to about 75%.

12. The imaging component army of claim 7, wherein the photosensing element fill factor is greater than 75%.

13. The imaging component array of claim 12, wherein the photosensing element fill factor is up to about 100%.

14. The imaging component array of claim 7, wherein the electronics circuitry is optimized for substantial parallel processing of array-captured images.

15. The imaging component array of claim 7, further comprising a plurality of vertically integrated optically active layers.

16. The imaging component array of claim 7, further comprising a plurality of vertically integrated electronic processing layers.

17. The imaging component array of claim 7, wherein said optically active, monocrystalline layer comprises at least one of Si, GaAs, InP, GaN, HgCdTe, Ge, SiGe, and SiC.

18. A electronic imaging component array, said component array comprising:

a plurality of electronics array layers;

a plurality of monocrystalline photosensing element arrays, said monocrystalline photosensing element arrays fabricated in a plurality of vertically integrated optically active layers and bonded to said electronics layers;

a plurality of substantially vertical interconnects coupled to said electronics array layers; and

said monocrystalline photosensing element arrays further comprising a plurality of junctions substantially surrounding and at least partially encompassing said plurality of vertical interconnects, wherein charge carriers may be substantially laterally drawn to the axes of at least one of said plurality of junction, and said plurality of vertical interconnects, said junctions including one of a p-type and an n-type material having a first side adjacent said vertical interconnect and the other of the one of a p-type and an n-type material adjacent a second side opposed to said first side and positioned horizontally from said first side.

19. The imaging component array of claim 18, wherein different optically active layers are suitably adapted to demonstrate sensitivity to different regions of the electromagnetic spectrum.

20. The imaging component array of claim 18, wherein said optically active, layers comprise at least one of Si, GaAs, InP, GaN, HgCdTe, Ge, SiGe, and Sic.