Methods of forming dislocation enhanced strain in NMOS and PMOS structures
Methods of forming a strained channel device utilizing dislocations disposed in source/drain structures are described. Those methods and structures may include forming a thin silicon germanium material in a source/drain opening of a device comprising silicon, wherein multiple dislocations are formed in the silicon germanium material. A source/drain material may be formed on the thin silicon germanium material, wherein the dislocations induce a tensile strain in a channel region of the device.
1. A fin Field Effect Transistor (finFET) comprising:
a single-crystal semiconductor substrate;
a finFET body extending from the single-crystal semiconductor substrate, the finFET body having a top and laterally opposite sidewalls extending from a source side to a drain side, the laterally opposite sidewalls adjacent to isolation regions;
a gate dielectric over the top and laterally opposite sidewalls of the finFET body;
a gate electrode over the gate dielectric;
sidewall spacers formed on the source and drain sides of the finFET body;
dislocation nucleation material selectively grown using epitaxial grown upon source and drain recesses that are recessed below a top of the isolation regions laterally adjacent to the source and drain sides of the finFET body, respectively, the dislocation nucleation material in contact with a bottom surface of the dielectric spacers and with a bottom surface of the gate dielectric, wherein the dislocation nucleation material comprises silicon-germanium;
source and drains materials formed on silicon-germanium dislocation nucleation layers, the source and drain materials having dislocations extending from the dislocation nucleation layers; wherein the dislocation material further comprises phosphorus and/or antimony, wherein the phosphorus and/or antimony has a concentration between 10 16 cm −3 and 10 21 cm −3 ; and wherein a lattice constant of the dislocation nucleation material is between 5.43 Å and 5.66 Å.
2. The finFET of claim 1 , wherein a germanium concentration of the silicon-germanium is between 10 and 80 atomic percent.
3. The finFET of claim 1 , wherein the dislocation nucleation material induces a tensile stress in a channel region along a conduction direction.
4. The finFET of claim 1 , wherein the source and drain materials comprise silicon and phosphorus.
5. The finFET of claim 1 , wherein the dislocation nucleation material comprises a lower portion comprising silicon germanium, phosphorus, and/or arsenic and an upper portion comprising silicon and phosphorus.
6. The finFET of claim 1 , further comprising:
a nano-wire structure.
7. The finFET of claim 6 , wherein the nano-wire structure comprises wrap-around nanowire material disposed underneath the gate dielectric.
8. The finFET of claim 7 , wherein the nano-wire structure further comprises a wrap-around gate dielectric disposed beneath the wrap-around nanowire material.
9. The finFET of claim 8 , wherein the nano-wire structure further comprises a wrap-around gate electrode disposed underneath the wrap-around gate dielectric.
10. The finFET of claim 1 , wherein a top of the source material is spaced apart from a top of the drain material by a first distance, and a bottom of the source material is spaced apart from a bottom of the drain material by a second distance greater than the first distance.