Integrated Image Sensor System on Common Substrate

• US 20100320444A1
• Filed: 06/22/2010
• Published: 12/23/2010
• Est. Priority Date: 06/22/2009
• Status: Active Grant

• Current Assignee: Banpil Photonics, Inc.
• Original Assignee: Banpil Photonics, Inc.
• Inventors: DUTTA, ACHYUT KUMAR
• Granted Patent: US 8,304,759 B2
• Time in Patent Office: Days
• US Class Current: 257/21
• CPC Class Codes: H01L 21/02521 Materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02603 Nanowires
• CPC Class Codes: H01L 25/042 the devices being arranged next to each other solar cells H01L31/042
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14607 Geometry of the photosensitive area
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/0352 characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
• CPC Class Codes: H01L 31/035281 Shape of the body
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: H01L 31/075 the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

It is highly desirable to design a monolithic image sensor (and array), which could offer high quantum efficiency over broad spectral ranges, and the possibility to rapidly and randomly address any element in the array. This invention utilizes the growth of semiconductor nanowires such as Si, Ge, Si:Ge, ZnO, or their alloys based nanowires on standard substrates to create multispectral image sensors and photovoltaic cells having these highly desirable features.

Claims

1. An image sensor comprising:

a conductive layer;

an array of pixels disposed on said conductive layer, wherein each pixel comprises a plurality of semiconductor nanowires and a metal contact disposed on said plurality of semiconductor nanowires;

insulator disposed between said pixels;

and a first conformal substrate disposed on said array of pixels.

2. An image sensor according to claim 1, further comprising a second substrate disposed below said conductive layer.

3. An image sensor according to claim 2, wherein said second substrate is selected from the group consisting of:

a dielectric substrate, a semiconductor substrate, and a metallic substrate.

4. An image sensor according to claim 2, wherein said second substrate is comprised of glass, and said conductive layer is comprised of ITO.

5. An image sensor according to claim 1, wherein said conformal substrate is a CMOS based ROIC.

6. An image sensor according to claim 1, wherein said semiconductor nanowires are comprised of a material selected from the group consisting of:

ZnO, ZnMgO, ZnBeO, ZnCdO, Si, Ge, Si;

Ge, and InP.

7. An image sensor according to claim 1, wherein said semiconductor nanowires comprise semiconductor junctions selected from the group consisting of:

p-n, p-i-n, p-i-p, n-i-n, Schottky, and a combination thereof.

8. An image sensor according to claim 1, wherein each of said semiconductor nanowires comprises more than one semiconductor type, thereby providing a semiconductor junction in each of said nanowires.

9. An image sensor according to claim 1, wherein the diameter of said nanowires is not less than 20 nanometers and not greater than 1000 nanometers, the height of said nanowires is not less than 200 nanometers and not greater than 5000 nanometers, and the pitch of said nanowires in a given pixel is not less than 20 nanometers and not greater than 1000 nanometers.

10. An image sensor according to claim 1, wherein said nanowires are selected from the group consisting of:

nanowires having varied diameters, nanowires having varied lengths, nanowires having varied pitches, and a combination thereof.

11. An image sensor according to claim 1, wherein said semiconductor nanowires are comprised of a material selected from the group consisting of:

ZnO, Si, Ge, Si;

Ge, InP, and their alloys.

12. An image sensor comprising:

a transparent substrate;

a transparent conductive layer disposed on said transparent substrate;

an array of pixels disposed on said transparent conductive layer, wherein each pixel comprises a plurality of semiconductor nanowires and a metal contact disposed on said plurality of semiconductor nanowires;

insulator disposed between said pixels;

and a CMOS carrier disposed on said array of pixels.

13. An image sensor according to claim 12, wherein said substrate is selected from the group consisting of:

a dielectric substrate, a semiconductor substrate, and a metallic substrate.

14. An image sensor according to claim 12, wherein each of said semiconductor nanowires comprises more than one semiconductor type, thereby providing a semiconductor junction in each of said nanowires.

15. An image sensor according to claim 12, wherein said semiconductor nanowires are comprised of a material selected from the group consisting of:

ZnO, ZnMgO, ZnBeO, ZnCdO, Si, Ge, Si;

Ge, and InP.

16. An image sensor according to claim 12, wherein said nanowires are selected from the group consisting of:

nanowires having varied diameters, nanowires having varied lengths, nanowires having varied pitches, and a combination thereof.

17. An image sensor according to claim 12, wherein said semiconductor nanowires are comprised of a material selected from the group consisting of:

ZnO, Si, Ge, Si;

Ge, InP, and their alloys.

18. An image sensor system comprising:

a common carrier;

power generation source disposed on said common carrier;

a CMOS carrier disposed on said common carrier;

a first image sensor disposed on said CMOS carrier, wherein said first image sensor is capable of infrared spectral detection;

and a second image sensor disposed on said CMOS carrier, wherein said second image sensor comprises;

an array of pixels disposed on said CMOS carrier, wherein each pixel comprises a metal contact disposed on said CMOS carrier and a plurality of semiconductor nanowires disposed on said metal contact;

insulator disposed between said pixels;

and a transparent conductive layer disposed on said array of pixels.

19. An image sensor system according to claim 18, wherein said power generation source is a photovoltaic cell comprising semiconductor nanowires.

20. An image sensor system according to claim 18, wherein said second image sensor further comprises a transparent substrate disposed on said transparent conductive layer.