Pinned photodiode CMOS pixel sensor
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.
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;
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;
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.
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;
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; and
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.
3. 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.
4. The multicolor CMOS pixel sensor of claim 3 wherein the body of semiconductor material is a semiconductor substrate.
5. 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.
6. The multicolor CMOS pixel sensor of claim 5 wherein the p-type semiconductor region is a p-well formed in a body of semiconductor material.
7. The multicolor CMOS pixel sensor of claim 6 wherein the body of semiconductor material is a semiconductor substrate.
8. 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 blue 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 green 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 red 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.
9. The multicolor CMOS pixel sensor of claim 8 wherein the p-type semiconductor region is a p-well formed in a body of semiconductor material.
10. The multicolor CMOS pixel sensor of claim 9 wherein the body of semiconductor material is a semiconductor substrate.
11. 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.
12. The multicolor CMOS pixel sensor of claim 11 , 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.
13. The multicolor CMOS pixel sensor of claim 11 , 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.
14. The multicolor CMOS pixel sensor of claim 13 , 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.