PINNED PHOTODIODE CMOS PIXEL SENSOR

• US 20080185619A1
• Filed: 02/07/2007
• Published: 08/07/2008
• Est. Priority Date: 02/07/2007
• Status: Active Grant

• Current Assignee: Foveon, Inc. (Avis Budget Group Incorporated)
• Original Assignee: Foveon, Inc. (Avis Budget Group Incorporated)
• Inventors: Merrill, Richard B.
• Granted Patent: US 8,115,242 B2
• Time in Patent Office: Days
• US Class Current: 257/292
• CPC Class Codes: H01L 27/14641 Electronic components shared by two or more pixel-elements, e.g. one amplifier shared by two pixel elements
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

A multicolor CMOS pixel sensor formed in a p-type semiconductor region includes a first detector formed from an n-type region of semiconductor material located near the surface of the p-type region. A first pinned p-type region is formed at the surface of the p-type region over the first detector, and has a surface portion extending past an edge of the pinned p-type region. A second detector is formed from an n-type region located in the p-type semiconductor region below the first detector. A second-detector n-type deep contact plug is in contact with the second detector and extends to the surface of the p-type semiconductor region. A second pinned p-type region is formed at the surface of the p-type semiconductor region over the top of the second-detector n-type deep contact plug. A surface portion of the second-detector deep contact plug extends past an edge of the second pinned p-type region.

Claims

1. A multicolor CMOS pixel sensor formed in a p-type semiconductor region, the multicolor CMOS pixel sensor including:

a first detector for a first color formed from an n-type region of semiconductor material located near the surface of the p-type semiconductor region;

a first pinned p-type region formed at the surface of the p-type semiconductor region over the first detector, a surface portion of the n-type region for the first detector extending past an edge of the pinned p-type region;

a second detector for a second color formed from an n-type region located in the p-type semiconductor region below the first detector;

a second-detector n-type deep contact plug in contact with the second detector and extending to the surface of the p-type semiconductor region; and

a second pinned p-type region formed at the surface of the p-type semiconductor region over the top of the second-detector n-type deep contact plug, a surface portion of the second-detector n-type deep contact plug extending past an edge of the second pinned p-type region.

2. The multicolor CMOS pixel sensor of claim 1, further including:

a first polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the n-type region for the first detector and with an edge of the n+ source/drain region to form a first-color select transistor; and

a second polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the second-detector n-type deep contact plug and with an edge of the n+ source/drain region to form a second-color select transistor.

3. The multicolor CMOS pixel sensor of claim 1, further including:

a third detector for a third color formed from an n-type region located in the p-type semiconductor region below the second detector;

a third-detector n-type deep contact plug in contact with the third detector and extending to the surface of the p-type semiconductor region;

a third pinned p-type region formed at the surface of the p-type semiconductor region over the top of the third-detector n-type deep contact plug near the surface of the p-type semiconductor region, a surface portion of the third-detector n-type deep contact plug extending past the edge of the pinned p-type region.

4. The multicolor CMOS pixel sensor of claim 3, further including a third polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the third-detector n-type deep contact plug and with an edge of the n+source/drain region to form a third-color select transistor.

5. The multicolor CMOS pixel sensor of claim 1 wherein the p-type semiconductor region is a p-well formed in a body of semiconductor material.

6. The multicolor CMOS pixel sensor of claim 5 wherein the body of semiconductor material is a semiconductor substrate.

7. A multicolor CMOS pixel sensor formed in a p-type semiconductor region on a semiconductor substrate, the multicolor CMOS pixel sensor including:

a blue detector formed from an n-type region of semiconductor material located near the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the blue detector, a surface portion of the blue-detector n-type region extending past an edge of the pinned p-type region;

a green detector formed from an n-type region located in the p-type semiconductor region below the blue detector;

a green-detector n-type deep contact plug in contact with the green detector and extending to the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the top of the green-detector n-type deep contact plug, a surface portion of the green-detector n-type deep contact plug extending past an edge of the pinned p-type region;

a red detector formed from an n-type region located in the p-type semiconductor region below the green detector;

a red-detector n-type deep contact plug in contact with the red detector and extending to the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the top of the red-detector n-type deep contact plug near the surface of the p-type semiconductor region, a surface portion of the red-detector n-type deep contact plug extending past the edge of the pinned p-type region.

8. The multicolor CMOS pixel sensor of claim 7 wherein the p-type semiconductor region is a p-well formed in a body of semiconductor material.

9. The multicolor CMOS pixel sensor of claim 8 wherein the body of semiconductor material is a semiconductor substrate.

10. A multicolor CMOS pixel sensor formed in a p-type semiconductor region on a semiconductor substrate, the multicolor CMOS pixel sensor including:

a blue detector formed from an n-type region of semiconductor material located near the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the blue detector, a surface portion of the blue-detector n-type region extending past an edge of the pinned p-type region;

a blue-select transistor n+ source/drain region spaced apart from the surface portion of the blue detector region;

a polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the blue detector region and with an edge of the n+ source/drain region spaced apart from the surface portion of the blue detector region to form a blue select transistor;

a green detector formed from an n-type region located in the p-type semiconductor region below the blue detector;

a green-detector n-type deep contact plug in contact with the green detector and extending to the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the top of the green-detector n-type deep contact plug, a surface portion of the green-detector n-type deep contact plug extending past an edge of the pinned p-type region;

a green-select transistor n+ source/drain region spaced apart from the surface portion of the green detector region;

a polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the green-detector n-type deep contact plug and with an edge of the n+ source/drain region to form a green select transistor;

a red detector formed from an n-type region located in the p-type semiconductor region below the green detector;

a red-detector n-type deep contact plug in contact with the red detector and extending to the surface of the p-type semiconductor region;

a pinned p-type region formed at the surface of the p-type semiconductor region over the top of the red-detector n-type deep contact plug near the surface of the p-type semiconductor region, a surface portion of the red-detector n-type deep contact plug extending past the edge of the pinned p-type region;

a red-select transistor n+ source/drain region spaced apart from the surface portion of the blue detector region;

a polysilicon gate electrode formed over and insulated from the surface of the p-type semiconductor region and self-aligned with an edge of the surface portion of the red-detector n-type deep contact plug and with an edge of the n+ source/drain region to form a red select transistor.

11. The multicolor CMOS pixel sensor of claim 10 wherein the p-type semiconductor region is a p-well formed in a body of semiconductor material.

12. The multicolor CMOS pixel sensor of claim 11 wherein the body of semiconductor material is a semiconductor substrate.