US 11,876,136 B2
Transistor having wrap-around source/drain contacts and under-contact spacers
Yi Song, Milpitas, CA (US); Praveen Joseph, White Plains, NY (US); Andrew Greene, Slingerlands, NY (US); and Kangguo Cheng, Schenectady, NY (US)
Assigned to International Business Machine Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Feb. 1, 2022, as Appl. No. 17/590,193.
Application 17/590,193 is a division of application No. 16/654,167, filed on Oct. 16, 2019, granted, now 11,296,226.
Prior Publication US 2022/0157985 A1, May 19, 2022
Int. Cl. H01L 29/78 (2006.01); H01L 29/66 (2006.01); H01L 29/08 (2006.01); H01L 29/10 (2006.01); H01L 21/8238 (2006.01); H01L 27/092 (2006.01)
CPC H01L 29/785 (2013.01) [H01L 21/823807 (2013.01); H01L 21/823814 (2013.01); H01L 21/823821 (2013.01); H01L 21/823871 (2013.01); H01L 27/0924 (2013.01); H01L 29/0847 (2013.01); H01L 29/1037 (2013.01); H01L 29/66795 (2013.01); H01L 2029/7858 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor device structure comprising:
a first channel region over a substrate;
a second channel region over the first channel region;
a source or drain (S/D) trench having a S/D trench region and a bottom trench region;
a liner within the bottom trench region;
wherein the liner comprises a first liner element on a bottom surface of the bottom trench region;
wherein the liner further comprises a second liner element on sidewalls of the bottom trench region;
an under-contact spacer on the first liner element and along first portions of the second liner element such that second portions of the second liner element extend above the under-contact spacer;
a merged S/D region within the S/D trench region and adjacent to the first channel region and the second channel region, wherein the merged S/D region comprises a top surface, sidewalls, and a bottom surface; and
a wrap-around S/D contact configured such that a portion of the wrap-around S/D contact is between the bottom surface of the merged S/D region and a bi-layer bottom spacer comprising the liner and the under-contact spacer.