US 11,757,036 B2
Moon-shaped bottom spacer for vertical transport field effect transistor (VTFET) devices
Ruilong Xie, Niskayuna, NY (US); Chen Zhang, Guilderland, NY (US); Julien Frougier, Albany, NY (US); Alexander Reznicek, Troy, NY (US); and Shogo Mochizuki, Mechanicville, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Jul. 29, 2021, as Appl. No. 17/388,572.
Prior Publication US 2023/0031574 A1, Feb. 2, 2023
Int. Cl. H01L 29/78 (2006.01); H01L 29/417 (2006.01); H01L 29/66 (2006.01)
CPC H01L 29/7827 (2013.01) [H01L 29/41741 (2013.01); H01L 29/41766 (2013.01); H01L 29/6653 (2013.01); H01L 29/66666 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A vertical transport field effect transistor (VTFET) device comprising:
at least one semiconductor fin extending upward from a surface of a substrate and located in a first active device region, wherein a trench isolation structure is located in the substrate and at an edge of the first active device region;
a bottom source/drain region located beneath, and on each side of, the at least one semiconductor fin;
a moon-shaped bottom spacer located laterally adjacent to a lower portion of at least a first side of the at least one semiconductor fin and above the bottom source/drain region, wherein the moon-shaped bottom spacer has a convex upper surface and a planar bottommost surface;
a functional gate structure contacting a middle portion of the at least one semiconductor fin and located on the convex upper surface of the moon-shaped bottom spacer;
a top spacer contacting an upper portion of the at least one semiconductor fin and on a surface of the functional gate structure; and
a top source/drain region contacting an upper surface of the at least one semiconductor fin.