US 12,495,543 B2
Method for manufacturing semiconductor memory device
Ho Kyun An, Hwaseong-si (KR); Su Min Cho, Seoul (KR); Bum Soo Kim, Gwacheon-si (KR); and Ha Young Kim, Yongin-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Sep. 1, 2022, as Appl. No. 17/929,270.
Claims priority of application No. 10-2021-0182310 (KR), filed on Dec. 20, 2021.
Prior Publication US 2023/0200059 A1, Jun. 22, 2023
Int. Cl. H10B 12/00 (2023.01)
CPC H10B 12/50 (2023.02) [H10B 12/09 (2023.02); H10B 12/315 (2023.02)] 20 Claims
OG exemplary drawing
 
10. A method for manufacturing a semiconductor memory device, the method comprising:
providing a substrate that includes a first region and a second region;
forming a first element isolation film that fills a first trench in the first region of the substrate and defines a first active area, wherein the first element isolation film includes a first liner that covers an inner sidewall and a bottom surface of the first trench;
forming a second element isolation film that fills a second trench in the second region of the substrate and defines a second active area, wherein the second element isolation film includes a second liner that covers an inner sidewall and a bottom surface of the second trench;
recessing the first liner and exposing a first corner portion in the first region of the substrate, and recessing the second liner and exposing a second corner portion in the second region of the substrate;
doping nitrogen onto an entire surface of the substrate;
forming a first pre-gate insulating film that extends along and on a first upper surface and the first corner portion in the first region of the substrate; and
forming a second pre-gate insulating film that extends along and on a second upper surface and the second corner portion in the second region of the substrate,
wherein the forming a first pre-gate insulating film and the forming a second pre-gate insulating film are distinct from each other such that a thickness of the first pre-gate insulating film is greater than a thickness of the second pre-gate insulating film,
wherein the first pre-gate insulating film includes a first portion on the first upper surface and a second portion on the first corner portion,
wherein a thickness of the first portion is less than a thickness of the second portion,
wherein the second pre-gate insulating film includes a third portion on the second upper surface and a fourth portion on the second corner portion, and
wherein a thickness of the third portion is less than a thickness of the fourth portion.