US 12,349,432 B2
Enlarged backside contact
Bwo-Ning Chen, Keelung (TW); Xusheng Wu, Hsinchu (TW); Yin-Pin Wang, Kaohsiung (TW); Yuh-Sheng Jean, Hsinchu (TW); and Chang-Miao Liu, Hsinchu (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Aug. 27, 2021, as Appl. No. 17/458,734.
Prior Publication US 2023/0060786 A1, Mar. 2, 2023
Int. Cl. H10D 64/01 (2025.01); H10D 30/01 (2025.01); H10D 30/67 (2025.01)
CPC H10D 64/01 (2025.01) [H10D 30/031 (2025.01); H10D 30/6729 (2025.01); H10D 30/6735 (2025.01); H10D 30/6757 (2025.01); H10D 30/6758 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
performing a first etching process on a backside of a substrate to form a trench to expose a dummy contact structure;
performing a first deposition process to deposit a first portion of an oxide layer to fill an entirety of the trench and around the dummy contact structure;
performing a second etching process to at least partially remove the first portion of the oxide layer, thereby exposing a sidewall of the dummy contact structure;
after performing the second etching process, depositing a spacer layer on the exposed sidewall of the dummy contact structure and around the dummy contact structure;
performing a second deposition process to form a second portion of the oxide layer around the spacer layer;
removing the spacer layer and the dummy contact structure to leave an opening; and
filling the opening with a conductive material to form a conductive plug.