US 12,142,486 B2
Nonvolatile semiconductor memory device and method of manufacturing the same
Takeshi Sonehara, Yokkaichi (JP); Takahiro Hirai, Yokkaichi (JP); Masaaki Higuchi, Yokkaichi (JP); and Takashi Shimizu, Kashiwa (JP)
Assigned to Kioxia Corporation, Tokyo (JP)
Filed by Kioxia Corporation, Tokyo (JP)
Filed on Oct. 3, 2023, as Appl. No. 18/479,871.
Application 18/479,871 is a division of application No. 17/183,599, filed on Feb. 24, 2021, abandoned.
Application 17/183,599 is a continuation of application No. 16/809,728, filed on Mar. 5, 2020, granted, now 10,957,556, issued on Mar. 23, 2021.
Application 16/809,728 is a continuation of application No. 16/235,435, filed on Dec. 28, 2018, granted, now 10,615,049, issued on Apr. 7, 2020.
Application 16/235,435 is a continuation of application No. 14/844,382, filed on Sep. 3, 2015, granted, now 10,192,753, issued on Jan. 29, 2019.
Claims priority of provisional application 62/050,335, filed on Sep. 15, 2014.
Prior Publication US 2024/0030040 A1, Jan. 25, 2024
Int. Cl. H01L 21/321 (2006.01); H10B 43/27 (2023.01)
CPC H01L 21/32105 (2013.01) [H10B 43/27 (2023.02)] 13 Claims
OG exemplary drawing
 
1. A method of manufacturing a semiconductor memory device comprising:
forming a plurality of first layers and a plurality of second layers alternately stacked in a first direction;
forming a hole penetrating the plurality of first layers and the plurality of second layers;
forming a charge accumulation layer and a semiconductor layer in the hole;
forming a trench penetrating the plurality of first layers and the plurality of second layers;
removing the plurality of first layers to form a plurality of removed areas at positions corresponding to the plurality of first layers;
forming a conductive material in the plurality of removed areas and in the trench;
recessing a part of the conductive material to form a conductive layer facing the semiconductor layer via the charge accumulation layer and having a rounded portion at an end on a side of the trench; and
forming an insulating material in the trench.