US 11,756,835 B2
Semiconductor device with air gaps between metal gates and method of forming the same
Wei-Lun Min, Hsinchu (TW); Xusheng Wu, Hsinchu (TW); and Chang-Miao Liu, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed on Jul. 11, 2022, as Appl. No. 17/861,679.
Application 17/861,679 is a division of application No. 16/931,703, filed on Jul. 17, 2020, granted, now 11,387,146.
Claims priority of provisional application 62/906,149, filed on Sep. 26, 2019.
Prior Publication US 2022/0344216 A1, Oct. 27, 2022
Int. Cl. H01L 21/8234 (2006.01); H01L 21/764 (2006.01); H01L 27/088 (2006.01)
CPC H01L 21/823481 (2013.01) [H01L 21/764 (2013.01); H01L 21/823431 (2013.01); H01L 27/0886 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
forming a gate stack over a first fin and a second fin;
removing a portion of the gate stack to form a trench extending between a first remaining portion of the gate stack disposed over the first fin and a second remaining portion of the gate stack disposed over the second fin;
forming a first material layer in the trench;
forming a second material layer on the first material layer disposed in the trench;
forming a third material layer on the second material layer disposed in the trench;
removing a first portion of the second material layer to form a first air gap extending from a first edge of the first material layer to a first edge of the third material layer; and
forming a sealing layer over the first air gap.