US 9,812,321 B2
Method for making nanosheet CMOS device integrating atomic layer deposition process and replacement gate structure
Bruce B. Doris, Slingerlands, NY (US); Michael A. Guillorn, Cold Springs, NY (US); Isaac Lauer, Yorktown Heights, NY (US); and Xin Miao, Guilderland, NY (US)
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed by INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed on Sep. 1, 2016, as Appl. No. 15/254,442.
Application 15/254,442 is a division of application No. 14/846,428, filed on Sep. 4, 2015, granted, now 9,647,139.
Prior Publication US 2017/0069734 A1, Mar. 9, 2017
Int. Cl. H01L 21/02 (2006.01); H01L 29/66 (2006.01); H01L 21/306 (2006.01); H01L 29/06 (2006.01); H01L 29/423 (2006.01); H01L 29/775 (2006.01); H01L 29/786 (2006.01)
CPC H01L 21/0228 (2013.01) [H01L 21/02603 (2013.01); H01L 21/30604 (2013.01); H01L 29/0673 (2013.01); H01L 29/42392 (2013.01); H01L 29/66439 (2013.01); H01L 29/66545 (2013.01); H01L 29/66795 (2013.01); H01L 29/775 (2013.01); H01L 29/78696 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of forming a semiconductor device comprising:
forming a replacement gate structure on a stack of at least two semiconductor materials, wherein a spacer is present on sidewalls of the replacement gate structure;
removing the replacement gate structure to provide a gate opening that exposes a channel portion of the stack of the two semiconductor materials;
applying a first etch process to remove one of the at least two semiconductor materials in the channel opening to provide suspended channel semiconductor layers, and a divot region undercutting the spacer between the suspended channel semiconductor layers;
forming an atomic layer deposited (ALD) conformal dielectric layer on sidewalls of the channel opening, wherein the ALD conformal dielectric layer fills the divot;
exposing sidewalls of the channel opening with a second etch process, wherein the divot remains filled with a remaining portion of the ALD conformal dielectric layer; and
forming a functional gate structure in the channel opening.