Semiconductor arrangement with isolation structure
A semiconductor arrangement includes a photodiode extending to a first depth from a first side in a substrate. An isolation structure laterally surrounds the photodiode and includes a first well that extends into a first side of the substrate. A deep trench isolation extends into a second side of the substrate and at least a portion of the deep trench isolation underlies the first well.
1. A semiconductor arrangement, comprising:
a photodiode extending to a first depth from a first side in a substrate;
an isolation structure laterally surrounding the photodiode, wherein the isolation structure comprises a first well extending to a second depth from the first side in the substrate greater than the first depth; and
a deep trench isolation extending from a third depth from the first side in the substrate to a fourth depth from the first side in the substrate, wherein at least a portion of the deep trench isolation underlies the first well.
2. The semiconductor arrangement of claim 1 , wherein the third depth is less than the second depth and the first well laterally surrounds the deep trench isolation.
3. The semiconductor arrangement of claim 1 , wherein the isolation structure has a first maximum width and the deep trench isolation has a second maximum width less than the first maximum width.
4. The semiconductor arrangement of claim 1 , wherein:
the substrate is arranged to receive radiation from a first direction,
the isolation structure comprises a shallow trench isolation,
the shallow trench isolation is tapered from a first maximum width to a first minimum width in a second direction opposite to the first direction, and
the deep trench isolation is tapered from a second minimum width to a second maximum width in the second direction.
5. The semiconductor arrangement of claim 1 , wherein:
the isolation structure comprises a shallow trench isolation, and
the isolation structure at least partially surrounds the shallow trench isolation.
6. The semiconductor arrangement according to claim 1 , wherein:
the photodiode is a first photodiode configured to detect a first range of wavelengths of radiation, and
the semiconductor arrangement comprises:
a second photodiode configured to detect a second range of wavelengths of radiation.
7. The semiconductor arrangement according to claim 6 , wherein the isolation structure and the deep trench isolation are between the first photodiode and the second photodiode.
8. The semiconductor arrangement according to claim 1 , wherein the substrate is a first-type epitaxial layer and the first well comprises a first-type dopant.
9. A semiconductor arrangement, comprising:
a photodiode array over a substrate, wherein the photodiode array comprises a first photodiode, a second photodiode, and a third photodiode;
an isolation structure disposed between the first photodiode and the second photodiode, wherein:
the isolation structure surrounds the third photodiode, and
the isolation structure comprises a first well and a shallow trench isolation at least partially surrounded by the first well; and
a near-infrared pass filter overlying the second photodiode and configured to allow a first range of wavelengths to pass through and be detected by the second photodiode.
10. The semiconductor arrangement of claim 9 , wherein:
the photodiode array comprises a first subset of photodiodes having a first lateral cross-sectional diameter and a second subset of photodiodes having a second lateral cross-sectional diameter,
the first photodiode and the third photodiode are members of the first subset of photodiodes, and
the second photodiode is a member of the second subset of photodiodes.
11. The semiconductor arrangement of claim 10 , wherein:
each photodiode of the first subset of photodiodes has a first lateral cross-sectional area, and
each photodiode of the second subset of photodiodes has a second lateral cross-sectional area less than the first lateral cross-sectional area.
12. The semiconductor arrangement of claim 10 , wherein:
each photodiode of the first subset of photodiodes has a first lateral cross-sectional area, and
each photodiode of the second subset of photodiodes has a second lateral cross-sectional area greater than the first lateral cross-sectional area.
13. The semiconductor arrangement of claim 10 , wherein:
each photodiode of the first subset of photodiodes has a corresponding overlying radiation pass filter, the radiation pass filter comprising one of:
a first radiation pass filter configured to allow a first radiation pass range of wavelengths to pass through and be detected by the corresponding photodiode,
a second radiation pass filter configured to allow a second radiation pass range of wavelengths to pass through and be detected by the corresponding photodiode, or
a third radiation pass filter configured to allow a third radiation pass range of wavelengths to pass through and be detected by the corresponding photodiode.
14. The semiconductor arrangement of claim 10 , wherein:
the isolation structure comprises:
a first subset of isolation structures surrounding the first subset of photodiodes and each of the first subset of isolation structures having a first lateral cross-sectional shape, and
a second subset of isolation structures surrounding the second subset of photodiodes and each of the second subset of isolation structures having a second lateral cross-sectional shape different from the first lateral cross-sectional shape.
15. The semiconductor arrangement of claim 14 , wherein the first subset of isolation structures includes a plurality of laterally contiguous isolation structures laterally surrounding the third photodiode.
16. The semiconductor arrangement of claim 9 , wherein the first well extends from a first side in the substrate, the semiconductor arrangement further comprising:
a deep trench isolation extending from a second side in the substrate, wherein at least a portion of the deep trench isolation overlaps and underlies the first well.
17. A method of making a semiconductor arrangement, comprising:
forming a first photodiode with a first depth from a first side in a substrate;
forming a first isolation structure laterally surrounding the first photodiode, wherein the first isolation structure comprises a first well extending to a second depth from the first side in the substrate greater than the first depth;
performing an etch into a second side in the substrate opposite the first side to form a deep trench, wherein the deep trench extends from a third depth from the first side in the substrate less than the second depth to the second side of the substrate, and wherein at least a portion of the deep trench underlies the first well;
forming a deep trench isolation in the deep trench; and
forming a near-infrared pass filter overlying the second side of the substrate and the first photodiode, wherein the near-infrared pass filter is configured to allow a first range of wavelengths to pass through and be detected by the first photodiode.
18. The method of claim 17 , wherein radiation enters the substrate from a first direction and from the second side of the substrate, the method further comprising:
performing the etch into the second side of the substrate, wherein the deep trench is tapered from a first maximum width to a first minimum width in the first direction.
19. The method of claim 17 , wherein radiation enters the substrate from a first direction and from the second side of the substrate, the method further comprising:
performing an etch into the first side of the substrate to form a shallow trench, wherein the shallow trench is tapered from a first maximum width to a first minimum width in a second direction opposite to the first direction; and
forming a shallow trench isolation in the shallow trench.
20. The method of claim 17 , further comprising:
forming the first isolation structure with a first lateral cross-sectional shape;
forming a second photodiode from the first side of the substrate;
forming a second isolation structure laterally surrounding the second photodiode, wherein the second isolation structure comprises a second well extending to the second depth from the first side in the substrate and has a second lateral cross-sectional shape; and
forming a radiation pass filter overlying the second side of the substrate and the second photodiode, the radiation pass filter comprising one of:
a first radiation pass filter configured to allow a first radiation pass range of wavelengths to pass through and be detected by the second photodiode,
a second radiation pass filter configured to allow a second radiation pass range of wavelengths to pass through and be detected by the second photodiode, or
a third radiation pass filter configured to allow a third radiation pass range of wavelengths to pass through and be detected by the second photodiode.