US 11,894,462 B2
Forming a sacrificial liner for dual channel devices
Huiming Bu, Glenmont, NY (US); Kangguo Cheng, Schenectady, NY (US); Dechao Guo, Niskayuna, NY (US); Sivananda K. Kanakasabapathy, Pleasanton, CA (US); and Peng Xu, Santa Clara, CA (US)
Assigned to Adeia Semiconductor Solutions LLC, San Jose, CA (US)
Filed by Adeia Semiconductor Solutions LLC, San Jose, CA (US)
Filed on Oct. 26, 2021, as Appl. No. 17/511,134.
Application 15/395,637 is a division of application No. 15/276,029, filed on Sep. 26, 2016, granted, now 9,773,893, issued on Sep. 26, 2017.
Application 17/511,134 is a continuation of application No. 16/685,229, filed on Nov. 15, 2019, granted, now 11,189,729.
Application 16/685,229 is a continuation of application No. 15/395,637, filed on Dec. 30, 2016, granted, now 10,510,892, issued on Dec. 17, 2019.
Prior Publication US 2022/0069118 A1, Mar. 3, 2022
Int. Cl. H01L 29/78 (2006.01); H01L 29/66 (2006.01); H01L 29/10 (2006.01); H01L 29/16 (2006.01); H01L 29/161 (2006.01); H01L 29/06 (2006.01); H01L 21/8234 (2006.01); H01L 21/8238 (2006.01); H01L 21/84 (2006.01); H01L 21/3065 (2006.01); H01L 21/324 (2006.01)
CPC H01L 29/785 (2013.01) [H01L 21/3065 (2013.01); H01L 21/324 (2013.01); H01L 21/823431 (2013.01); H01L 21/823821 (2013.01); H01L 21/845 (2013.01); H01L 29/0649 (2013.01); H01L 29/0653 (2013.01); H01L 29/1037 (2013.01); H01L 29/16 (2013.01); H01L 29/161 (2013.01); H01L 29/66795 (2013.01); H01L 29/66818 (2013.01); H01L 29/7851 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
providing a substrate having thereon a layer of epitaxial channel material;
patterning a hardmask above the layer of epitaxial channel material;
performing a first etch to a first depth, using the hardmask as a mask, to form an upper portion of a fin, wherein the first depth extends beyond a bottom surface of the layer of epitaxial channel material;
forming a liner over exposed surfaces of the upper portion of the fin;
performing a second etch to a second depth, using the liner as a mask, to form a lower portion of the fin;
removing the liner; and
forming a gate dielectric on exposed surfaces of the upper portion of the fin, wherein the gate dielectric extends beyond the bottom surface of the layer of epitaxial channel material.