US 12,274,059 B2
Semiconductor storage device and method of manufacturing semiconductor storage device
Tomohiro Kuki, Yokkaichi (JP); Tatsufumi Hamada, Nagoya (JP); Shinichi Sotome, Yokkaichi (JP); Yosuke Mitsuno, Yokkaichi (JP); and Muneyuki Tsuda, Ichinomiya (JP)
Assigned to Kioxia Corporation, Tokyo (JP)
Filed by Kioxia Corporation, Tokyo (JP)
Filed on Mar. 17, 2021, as Appl. No. 17/204,015.
Claims priority of application No. 2020-144747 (JP), filed on Aug. 28, 2020.
Prior Publication US 2022/0068964 A1, Mar. 3, 2022
Int. Cl. H10B 51/20 (2023.01); H01L 21/306 (2006.01); H01L 21/311 (2006.01); H10B 41/27 (2023.01); H10B 43/27 (2023.01)
CPC H10B 43/27 (2023.02) [H01L 21/30604 (2013.01); H01L 21/31111 (2013.01); H10B 41/27 (2023.02); H10B 51/20 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A semiconductor storage device comprising:
a substrate;
a first electric charge holder, at least a part of the first electric charge holder being curved in a first cross section along a surface of the substrate;
a channel layer inside the first electric charge holder in the first cross section, at least a part of the channel layer being curved in the first cross section; and
a first conductor provided outside an entire circumference of the first electric charge holder in the first cross section,
wherein
the first electric charge holder has a curvature varying in accordance with a position in the first cross section,
the channel layer has a film thickness varying in accordance with the curvature of the first electric charge holder in the first cross section,
the first electric charge holder includes, in the first cross section, a first part and a second part, the second part having a larger curvature than the first part,
the channel layer includes, in the first cross section, a first part and a second part, the first part of the channel layer being alongside the first part of the first electric charge holder, the second part of the channel layer being alongside the second part of the first electric charge holder, and
the second part of the channel layer has a larger film thickness than the first part of the channel layer, and
a difference between film thicknesses at the first part and the second part of the channel layer is larger than a difference between film thicknesses at the first part and the second part of the first electric charge holder.