Integrated single diffusion break
A methodology for forming a fin field effect transistor (FinFET) includes the co-integration of various isolation structures, including gate cut and shallow diffusion break isolation structures that are formed with common masking and etching steps. Following an additional patterning step to provide segmentation for source/drain conductive contacts, a single deposition step is used to form an isolation dielectric layer within each of gate cut openings, shallow diffusion break openings and cavities over shallow trench isolation between device active areas.
1. A semiconductor device comprising:
a plurality of semiconductor fins disposed over a semiconductor substrate, the semiconductor fins each having a source/drain region and a channel region adjacent to the source/drain region;
a shallow trench isolation layer disposed over a top surface of the semiconductor substrate and peripheral to lower portions of the fins;
a gate stack disposed over the channel regions, wherein the gate stack comprises a gate dielectric layer, a work function metal layer overlying the gate dielectric layer, and a conductive fill layer overlying the work function metal layer;
a gate cap disposed over the gate stack; and
an isolation dielectric layer extending through the gate stack, wherein the isolation dielectric layer is disposed directly over sidewalls of the conductive fill layer.
2. The semiconductor device of claim 1 , wherein the isolation dielectric layer is in direct contact with a portion of the work function metal layer.
3. The semiconductor device of claim 1 , wherein a top surface of at least one of the fins is disposed below a top surface of the shallow trench isolation layer and the isolation dielectric is disposed over the top surface of the at least one of the fins.
4. The semiconductor device of claim 1 , wherein a top surface of at least one of the fins is disposed below a top surface of the shallow trench isolation layer and the isolation dielectric is spaced away from the top surface of the at least one of the fins.
5. The semiconductor device of claim 1 , wherein the isolation dielectric extends continuously from sidewalls of the gate cap to a top surface of the shallow trench isolation layer.
6. The semiconductor device of claim 1 , further comprising a conductive contact disposed over the source/drain region.
7. A semiconductor device comprising:
a gate stack disposed over a channel region of a semiconductor layer, wherein the gate stack comprises a gate dielectric layer, a work function metal layer overlying the gate dielectric layer, and a conductive fill layer overlying the work function metal layer; and
an isolation dielectric layer extending through the gate stack, wherein the isolation dielectric layer is disposed directly over sidewalls of the conductive fill layer.
8. The semiconductor device of claim 7 , wherein the semiconductor layer comprises a semiconductor fin.
9. The semiconductor device of claim 7 , wherein the isolation dielectric extends from sidewalls a gate cap overlying the gate stack to a top surface of a shallow trench isolation layer underlying the gate stack.