US 12,243,941 B2
Conformal oxidation for gate all around nanosheet I/O device
Myungsun Kim, Pleasanton, CA (US); Michael Stolfi, Clifton Park, NY (US); Benjamin Colombeau, San Jose, CA (US); and Andy Lo, Saratoga, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jul. 28, 2021, as Appl. No. 17/386,711.
Claims priority of provisional application 63/060,087, filed on Aug. 2, 2020.
Prior Publication US 2022/0037529 A1, Feb. 3, 2022
Int. Cl. H01L 29/78 (2006.01); H01L 21/02 (2006.01); H01L 21/8234 (2006.01); H01L 29/06 (2006.01); H01L 29/15 (2006.01); H01L 29/16 (2006.01); H01L 29/423 (2006.01); H01L 29/786 (2006.01); H01L 29/66 (2006.01)
CPC H01L 29/7851 (2013.01) [H01L 21/02164 (2013.01); H01L 21/02236 (2013.01); H01L 21/02252 (2013.01); H01L 21/02301 (2013.01); H01L 21/823431 (2013.01); H01L 29/0673 (2013.01); H01L 29/157 (2013.01); H01L 29/1604 (2013.01); H01L 29/42392 (2013.01); H01L 29/78696 (2013.01); H01L 29/66545 (2013.01); H01L 2029/7858 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of forming a semiconductor device, comprising:
selectively etching a superlattice structure comprising a plurality of first layers and a corresponding plurality of second layers alternatingly arranged in a plurality of stacked pairs to remove each of the second layers to form a plurality of voids in the superlattice structure, the plurality of first layers extending between a source region and a drain region, and each of the plurality of first layers separated by a silicon oxide (SiOx) inner spacer;
pre-cleaning the plurality of first layers and silicon oxide (SiOx) inner spacer to remove native oxide and/or residues; and
conformally forming an oxide layer on the plurality of first layers and converting the silicon oxide (SiOx) inner spacer to a low-k dielectric inner spacer by radical plasma oxidation (RPO) of the plurality of first layers and the silicon oxide (SiOx) inner spacer, the radical plasma oxidation occurring at a temperature in a range of from about 700° C. to about 900° C. in an atmosphere of hydrogen (H2) gas and oxygen (O2) gas at ambient pressure,
wherein the method is performed in a processing chamber without breaking vacuum.