US 12,191,196 B2
Method of manufacturing a metal-oxide-semiconductor field-effect transistor (MOSFET) having low off-state capacitance
Gulbagh Singh, Tainan (TW); Tsung-Han Tsai, Miaoli (TW); Shih-Lu Hsu, Tainan (TW); and Kun-Tsang Chuang, Miaoli (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Jul. 27, 2022, as Appl. No. 17/815,274.
Application 17/815,274 is a division of application No. 17/248,079, filed on Jan. 7, 2021, granted, now 11,476,157.
Prior Publication US 2022/0367242 A1, Nov. 17, 2022
Int. Cl. H01L 21/768 (2006.01); H01L 21/285 (2006.01); H01L 23/532 (2006.01); H01L 23/535 (2006.01); H01L 29/45 (2006.01); H01L 29/78 (2006.01)
CPC H01L 21/7682 (2013.01) [H01L 21/28518 (2013.01); H01L 21/76805 (2013.01); H01L 21/76895 (2013.01); H01L 23/5329 (2013.01); H01L 23/535 (2013.01); H01L 29/45 (2013.01); H01L 29/78 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor device, comprising:
a source on a first side of a gate;
a drain on a second side of the gate, the second side of the gate being opposite to the first side of the gate;
a first contact over the source;
a second contact over the drain;
an air gap over the gate between at least the first contact and the second contact;
at least two dielectric materials in each of a region between the air gap and the first contact and a region between the air gap and the second contact; and
a liner layer that is over the first contact and the second contact and that is under the air gap.
 
13. A semiconductor device comprising:
a first contact on a first side of a gate;
a second contact on a second side of the gate;
a first dielectric material, between the first contact and the second contact, comprising a first portion adjacent to the first contact and a second portion adjacent to the second contact;
a second dielectric material between the first portion of the first dielectric material and the second portion of the first dielectric material, the second dielectric material being over the gate,
wherein a dielectric constant of the first dielectric material is greater than a dielectric constant of the second dielectric material; and
a liner layer that is over the first contact and the second contact.
 
20. A semiconductor device, comprising:
a source and a drain that are each on a gate;
an air gap over the gate between a first contact, over the source, and a second contact over the drain;
a dielectric material in a region between the air gap and the first contact and a region between the air gap and the second contact; and
a liner layer that is over the first contact and the second contact and that is under the air gap.