US 12,261,121 B2
Structure and method for a low-k dielectric with pillar-type air-gaps
Chih Wei Lu, Hsinchu (TW); Chung-Ju Lee, Hsinchu (TW); and Tien-I Bao, Taoyuan (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Jul. 28, 2023, as Appl. No. 18/361,088.
Application 18/361,088 is a division of application No. 17/080,051, filed on Oct. 26, 2020, granted, now 11,728,271.
Application 15/096,703 is a division of application No. 13/925,457, filed on Jun. 24, 2013, granted, now 9,312,220, issued on Apr. 12, 2016.
Application 17/080,051 is a continuation of application No. 15/096,703, filed on Apr. 12, 2016, granted, now 10,818,600, issued on Oct. 27, 2020.
Claims priority of provisional application 61/778,198, filed on Mar. 12, 2013.
Prior Publication US 2023/0369228 A1, Nov. 16, 2023
Int. Cl. H01L 21/76 (2006.01); H01L 21/311 (2006.01); H01L 21/768 (2006.01); H01L 23/522 (2006.01); H01L 23/528 (2006.01); H01L 23/532 (2006.01); H01L 23/535 (2006.01); H01L 23/485 (2006.01)
CPC H01L 23/535 (2013.01) [H01L 21/31144 (2013.01); H01L 21/7682 (2013.01); H01L 23/5222 (2013.01); H01L 23/528 (2013.01); H01L 23/5329 (2013.01); H01L 23/53295 (2013.01); H01L 21/76807 (2013.01); H01L 21/76885 (2013.01); H01L 23/485 (2013.01); H01L 2924/0002 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An interconnect structure comprising:
a dielectric layer having a first thickness;
a first interconnect and a second interconnect disposed in the dielectric layer, wherein each of the first interconnect and the second interconnect has:
a first portion having a first width and a second thickness, and
a second portion disposed over the first portion, wherein the second portion has a second width and a third thickness, the second width is greater than the first width, and a sum of the second thickness and the third thickness is equal to the first thickness of the dielectric layer;
a first air gap and a second air gap disposed in the dielectric layer, wherein the first air gap and the second air gap are disposed between the first interconnect and the second interconnect and each of the first air gap and the second air gap have a first height that is equal to the first thickness of the dielectric layer;
a third air gap disposed in the dielectric layer, wherein the third air gap has a second height that is less than the first thickness and equal to the second thickness; and
a cap dielectric layer abutting the dielectric layer, the first interconnect, the second interconnect, the first air gap, the second air gap, and the third air gap, wherein a composition of the cap dielectric layer is different than a composition of the dielectric layer.