US 11,901,408 B2
Self-aligned contact air gap formation
Kai-Hsuan Lee, Hsinchu (TW); Bo-Yu Lai, Taipei (TW); Sai-Hooi Yeong, Hsinchu County (TW); Feng-Cheng Yang, Hsinchu County (TW); Yih-Ann Lin, Hsinchu County (TW); and Yen-Ming Chen, Hsin-Chu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed on Feb. 15, 2021, as Appl. No. 17/175,831.
Application 17/175,831 is a division of application No. 16/144,642, filed on Sep. 27, 2018, granted, now 10,923,565.
Prior Publication US 2021/0183996 A1, Jun. 17, 2021
Int. Cl. H01L 29/06 (2006.01); H01L 29/66 (2006.01); H01L 21/8238 (2006.01); H01L 23/10 (2006.01); H01L 21/768 (2006.01); H01L 21/764 (2006.01)
CPC H01L 29/0649 (2013.01) [H01L 21/764 (2013.01); H01L 21/7682 (2013.01); H01L 21/76841 (2013.01); H01L 21/76897 (2013.01); H01L 21/823864 (2013.01); H01L 21/823871 (2013.01); H01L 23/10 (2013.01); H01L 29/6656 (2013.01); H01L 29/6681 (2013.01); H01L 29/66545 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A device comprising:
a source/drain feature disposed on a substrate;
a gate stack disposed on the substrate and associated with the source/drain feature, the gate stack extending to a first height above the substrate;
a first interlayer dielectric layer disposed over the substrate;
a contact feature extending through the first interlayer dielectric layer to the source/drain feature;
an air gap disposed between the gate stack and the contact feature, the air gap extending from the source/drain feature to a second height above the substrate that is greater than the first height of the gate stack, the source/drain feature being exposed to the air gap;
a nitride layer disposed directly on and extending along a sidewall of the contact feature, the nitride layer exposed to the air gap; and
a seal layer disposed directly on the first interlayer dielectric layer, the nitride layer and the contact feature, the seal layer sealing the air gap such that the seal layer is exposed to the air gap.