US Patent 9865705 Vertical field effect transistors with bottom source/drain epitaxy

A vertical fin field-effect-transistor and a method for fabricating the same. The vertical fin field-effect-transistor includes a substrate, a first source/drain layer including a plurality of pillar structures, and a plurality of fins disposed on and in contact with the plurality of pillar structures. A doped layer epitaxially grown from the first source/drain layer is in contact with the plurality of fins and the plurality of pillar structures. A gate structure is disposed in contact with two or more fins in the plurality of fins. The gate structure includes a dielectric layer and a gate layer. A second source/drain layer is disposed on the gate structure. The method includes epitaxially growing a doped layer in contact with a plurality of fins and a plurality of pillar structures. A gate structure is formed in contact with two or more fins. A second source/drain layer is formed on the gate structure.