US 12,074,203 B2
Nitride crystal, optical device, semiconductor device, and method for manufacturing nitride crystal
Toshiki Hikosaka, Kawasaki (JP); Shinya Nunoue, Ichikawa (JP); Tomoyuki Tanikawa, Suita (JP); Ryuji Katayama, Suita (JP); and Masahiro Uemukai, Suita (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and OSAKA UNIVERSITY, Osaka (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and OSAKA UNIVERSITY, Suita (JP)
Filed on Apr. 5, 2023, as Appl. No. 18/295,879.
Application 18/295,879 is a division of application No. 17/141,273, filed on Jan. 5, 2021, granted, now 11,677,006.
Claims priority of application No. 2020-032021 (JP), filed on Feb. 27, 2020.
Prior Publication US 2023/0261058 A1, Aug. 17, 2023
Int. Cl. H01L 29/20 (2006.01); C23C 16/30 (2006.01); G02F 1/355 (2006.01); G02F 1/37 (2006.01); H01L 21/02 (2006.01)
CPC H01L 29/2003 (2013.01) [C23C 16/303 (2013.01); G02F 1/3551 (2013.01); G02F 1/37 (2013.01); H01L 21/02389 (2013.01); H01L 21/02458 (2013.01); H01L 21/0254 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A nitride crystal, comprising:
a first nitride crystal region;
a second nitride crystal region; and
a third nitride crystal region provided between the first nitride crystal region and the second nitride crystal region, the third nitride crystal region including Al,
a third oxygen concentration in the third nitride crystal region being greater than a first oxygen concentration in the first nitride crystal region and greater than a second oxygen concentration in the second nitride crystal region,
a third carbon concentration in the third nitride crystal region being greater than a first carbon concentration in the first nitride crystal region and greater than a second carbon concentration in the second nitride crystal region,
a <0001> direction of the first nitride crystal region being one of a first orientation from the second nitride crystal region toward the first nitride crystal region or a second orientation from the first nitride crystal region toward the second nitride crystal region,
a <0001> direction of the second nitride crystal region being the other of the first orientation or the second orientation,
the first oxygen concentration being less than the second oxygen concentration, and
the first carbon concentration being more than the second carbon concentration.