Gate-all-around fin device
A gate-all around fin double diffused metal oxide semiconductor (DMOS) devices and methods of manufacture are disclosed. The method includes forming a plurality of fin structures from a substrate. The method further includes forming a well of a first conductivity type and a second conductivity type within the substrate and corresponding fin structures of the plurality of fin structures. The method further includes forming a source contact on an exposed portion of a first fin structure. The method further comprises forming drain contacts on exposed portions of adjacent fin structures to the first fin structure. The method further includes forming a gate structure in a dielectric fill material about the first fin structure and extending over the well of the first conductivity type.
1. A structure comprising:
a substrate of a first conductivity type;
a central well of the first conductivity type located in the substrate of the first conductivity type;
a doped well ring of a second conductivity type formed in the substrate and enclosing the central well of the first conductivity type;
a doped well region formed in the substrate adjacent the doped well ring, wherein the doped well ring is interposed between the doped well region and the central well;
a first doped fin contact region of the first conductivity type forming a source contact for a first fin forming a source and located over the central well of the first conductivity type; and
a second doped fin contact region of the second conductivity type forming drain contact regions for a second fin forming a drain and located over the doped well ring, wherein the drain contact regions include alternating p regions and n regions formed directly on the second fin.
2. The structure of claim 1 , further comprising a gate structure formed over the central well and around the first fin, wherein the gate structure is in a dielectric fill material.
3. The structure of claim 1 , further comprising a shallow trench isolation (STI) structure in the doped well ring.
4. The structure of claim 2 , wherein the doped well is of the first conductivity type.
5. The structure of claim 4 , wherein:
the first conductivity type is formed as a deep N-well and the second conductivity type as a P-well; and
the gate structure is formed partially over the deep N-well and the P-well.
6. The structure of claim 5 , wherein the deep N-well is formed as a ring surrounding the P-well.
7. The structure of claim 4 , wherein:
the first conductivity type is formed as a continuous deep N-well and the second conductivity type as a P-well; and
the gate structure is formed completely over the deep N-well.
8. The structure of claim 4 , wherein:
the first conductivity type is formed as a shallow N-well and the second conductivity type is a P-well;
the gate structure is formed partially over the shallow N-well and the P-well; and
the shallow N-well is a ring structure.
9. The structure of claim 4 , wherein:
the first conductivity type is formed as a continuous shallow N-well and the second conductivity type as a P-well;
the gate structure is formed entirely over the shallow N-well; and
the first fin structure comprising the source contact is formed completely over the shallow N-well.
10. The structure of claim 2 , wherein the gate structure is formed over an insulating layer above the central well and is structured vertically around the first fin.
11. The structure of claim 3 , wherein a first portion of the STI structure is located between the first fin and the second fin.
12. The structure of claim 11 , wherein a second portion of the STI structure is in contact with a portion of the second fin and extends over the doped well region.
13. The structure of claim 12 , wherein the first portion of the STI structure extends into the doped well ring and under a lower portion of the gate structure.
14. The structure of claim 2 , wherein the first doped fin contact region is formed to extend over both an upper surface of the gate structure and an upper surface of the first fin.