International Business Machines Corporation
BOTTOM SOURCE/DRAIN FOR FIN FIELD EFFECT TRANSISTORS

Abstract:

A method of forming a vertical transport fin field effect transistor device is provided. The method includes forming vertical fins on a substrate, depositing a protective liner on the sidewalls of the vertical fins, and removing a portion of the substrate to form a support pillar beneath at least one of the vertical fins. The method further includes etching a cavity in the support pillar of the at least one of the vertical fins, and removing an additional portion of the substrate to form a plinth beneath the support pillar of the vertical fin. The method further includes growing a bottom source/drain layer on the substrate adjacent to the plinth, and forming a diffusion plug in the cavity, wherein the diffusion plug is configured to block diffusion of dopants from the bottom source/drain layer above a necked region in the support pillar.