Nanosheet devices with CMOS epitaxy and method of forming
This disclosure relates to a method of forming nanosheet devices including: forming a first and second nanosheet stack on a substrate, the first and the second nanosheet stacks including a plurality of vertically spaced nanosheets disposed on the substrate and separated by a plurality of spacing members, each of the plurality of spacing members including a sacrificial layer and a pair of inner spacers formed on lateral ends of the sacrificial layer; growing a pair of epitaxial regions adjacent to the first and second nanosheet stacks from each of the plurality of nanosheets such that each of the plurality of inner spacers is enveloped by one of the epitaxial regions; covering the first nanosheet stack with a mask; and forming a pair of p-type source/drain regions on the second nanosheet stack, each of the pair of p-type source/drain regions being adjacent to the epitaxial regions on the second nanosheet stack.
1. A semiconductor device comprising:
a first and second nanosheet stack on a substrate, the first and the second nanosheet stack being adjacent to each other and each including vertically spaced nanosheets;
a pair of semiconductor layers disposed on the second nanosheet stack in contact with sidewalls of the nanosheets of the second nanosheet stack, each of the pair of semiconductor layers extending vertically from a lowermost nanosheet of the second nanosheet stack to an uppermost nanosheet of the second nanosheet stack;
a pair of n-type source/drain regions disposed on the substrate adjacent to the first nanosheet stack; and
a pair of p-type source/drain regions disposed on the substrate adjacent to the second nanosheet stack and in direct contact with the pair of semiconductor layers.
2. The semiconductor device of claim 1 , wherein the p-type source/drain regions include boron-doped silicon germanium (SiGe).
3. The semiconductor device of claim 2 , further comprising a pair of semiconductor layers disposed on the first nanosheet stack in contact with sidewalls of the nanosheets of the first nanosheet stack, each of the pair of semiconductor layers extending vertically from a lowermost nanosheet of the first nanosheet stack to an uppermost nanosheet of the first nanosheet stack, wherein the pair of semiconductor layers on the first nanosheet stack includes n-type dopants.
4. The semiconductor device of claim 2 , wherein the pair of semiconductor layers on the second nanosheet stack includes p-type dopants.
5. The semiconductor device of claim 1 , wherein the pair of semiconductor layers is a first pair of semiconductor layers, and the semiconductor device further comprises: a second pair of semiconductor layers disposed on the first nanosheet stack in contact with sidewalls of the nanosheets of the first nanosheet stack, between the sidewalls of the nanosheets of the first nanosheet stack and the pair of n-type source/drain regions, each of the second pair of semiconductor layers extending vertically from a lowermost nanosheet of the first nanosheet stack to an uppermost nanosheet of the first nanosheet stack.
6. The semiconductor device of claim 5 , wherein the pair of n-type source/drain regions are in direct contact with the second pair of semiconductor layers.
7. The semiconductor device of claim 1 , wherein the first nanosheet stack is adjacent to the second nanosheet stack.
8. The of claim 7 , wherein the first nanosheet stack includes a NFET device, and the second nanosheet stack includes a PFET device.
9. The semiconductor device of claim 7 , wherein the nanosheets of the second nanosheet stack include partial n-type doping.
10. The semiconductor device of claim 1 , further comprising a plurality of spacing members between each of the nanosheets, each of the plurality of spacing members including a metal gate material and a pair of inner spacers disposed on lateral ends of the metal gate material, and wherein the pair of semiconductor layers envelope each of the inner spacers of the second nanosheet stack.