US 12,255,138 B2
Interconnect structures of semiconductor device and methods of forming the same
Chia-Cheng Chou, Keelung (TW); Chung-Chi Ko, Nantou (TW); and Tze-Liang Lee, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Sep. 26, 2023, as Appl. No. 18/474,265.
Application 18/474,265 is a division of application No. 17/732,556, filed on Apr. 29, 2022, granted, now 11,923,294.
Application 17/732,556 is a continuation of application No. 16/801,166, filed on Feb. 26, 2020, granted, now 11,373,947, issued on Jun. 28, 2022.
Prior Publication US 2024/0014125 A1, Jan. 11, 2024
Int. Cl. H01L 23/522 (2006.01); H01L 21/768 (2006.01); H01L 23/528 (2006.01)
CPC H01L 23/5226 (2013.01) [H01L 21/76807 (2013.01); H01L 23/528 (2013.01); C04B 2235/61 (2013.01); G01V 2210/6242 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of forming an interconnect structure, comprising:
depositing a first etching stop layer over a substrate;
depositing a first dielectric layer over the first etching stop layer;
depositing a second etching stop layer over the first dielectric layer;
depositing an insert layer and a second dielectric layer over the second etching stop layer;
patterning the second dielectric layer, the insert layer, the second etching stop layer, the first dielectric layer and the first etching stop layer, thereby forming a trench opening in the second dielectric layer and the insert layer, a via hole in the second etching stop layer, the first dielectric layer and the first etching stop layer, and a stack on the second etching stop layer and laterally beside the trench opening, wherein the stack has an aspect ratio greater than 2; and
filling a conductive feature in the trench opening and the via hole, thereby forming a conductive line in the second dielectric layer and the insert layer, and a via in the first etching stop layer and the first dielectric layer,
wherein a material of the insert layer is different from materials of the second dielectric layer and the second etch stop layer.