US 12,249,559 B2
Conductive features with air spacer and method of forming same
Hsiang-Wei Lin, New Taipei (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Jan. 5, 2022, as Appl. No. 17/568,984.
Claims priority of provisional application 63/229,662, filed on Aug. 5, 2021.
Prior Publication US 2023/0038952 A1, Feb. 9, 2023
Int. Cl. H01L 23/482 (2006.01); H01L 21/762 (2006.01)
CPC H01L 23/4821 (2013.01) [H01L 21/76289 (2013.01); H01L 23/4828 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
etching a dielectric layer to form an opening, wherein the opening exposes a surface of a first conductive feature underlying the dielectric layer;
depositing a sacrificial layer on sidewalls of the opening;
forming a second conductive feature in the opening, wherein the second conductive feature physically and electrically contacts the first conductive feature;
removing the sacrificial layer to form an air spacer surrounding the second conductive feature;
forming an inhibitor material on the second conductive feature, wherein the inhibitor material laterally extends at least partially over the air spacer;
forming a first etch stop material on the dielectric layer, wherein the inhibitor material blocks formation of the first etch stop material on the inhibitor material;
removing the inhibitor material; and
forming a metal cap on the second conductive feature, wherein the metal cap laterally extends over the air spacer, wherein forming the metal cap seals the air spacer with the metal cap.