US 11,798,910 B2
Self-aligned interconnect structure
Hsin-Chieh Yao, Hsinchu (TW); Chung-Ju Lee, Hsinchu (TW); Chih Wei Lu, Hsinchu (TW); Hsi-Wen Tien, Xinfeng Township (TW); Yu-Teng Dai, New Taipei (TW); and Wei-Hao Liao, Taichung (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Jul. 20, 2022, as Appl. No. 17/868,946.
Application 17/868,946 is a division of application No. 16/898,670, filed on Jun. 11, 2020, granted, now 11,488,926.
Prior Publication US 2022/0352113 A1, Nov. 3, 2022
Int. Cl. H01L 23/00 (2006.01); H01L 21/768 (2006.01); H01L 23/522 (2006.01)
CPC H01L 24/48 (2013.01) [H01L 21/76802 (2013.01); H01L 21/76877 (2013.01); H01L 21/76808 (2013.01); H01L 21/76897 (2013.01); H01L 23/5226 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for forming a semiconductor structure, the method comprising:
forming a first metal line in a first dielectric layer and over a substrate;
depositing a second dielectric layer comprising a first dielectric material over the first dielectric layer and the first metal line;
forming a first opening and a second opening in the second dielectric layer, the first opening and the second opening extending through the second dielectric layer, into the first dielectric layer on opposite sides of the first metal line, and below a top surface of the first metal line;
forming a first protective dielectric structure and a second protective dielectric structure in the first opening and the second opening, respectively, wherein the first protective dielectric structure and the second protective dielectric structure comprise a protective dielectric material different from the first dielectric material;
forming a third opening in the second dielectric layer, the third opening extending through the second dielectric layer to the first metal line and directly between the first protective dielectric structure and the second protective dielectric structure; and
forming a first metal via in the third opening, the first metal via electrically coupled to the first metal line.