US 11,862,689 B2
Group-III element nitride semiconductor substrate
Katsuhiro Imai, Nagoya (JP); Masahiro Sakai, Nagoya (JP); and Hiroki Kobayashi, Nagoya (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Feb. 17, 2023, as Appl. No. 18/170,819.
Application 18/170,819 is a continuation of application No. PCT/JP2021/016074, filed on Apr. 20, 2021.
Claims priority of application No. 2020-156017 (JP), filed on Sep. 17, 2020.
Prior Publication US 2023/0282711 A1, Sep. 7, 2023
Int. Cl. H01L 21/02 (2006.01); H01L 29/20 (2006.01); H01L 29/06 (2006.01); H01L 21/304 (2006.01)
CPC H01L 29/2003 (2013.01) [H01L 21/0237 (2013.01); H01L 21/0242 (2013.01); H01L 21/0243 (2013.01); H01L 21/0254 (2013.01); H01L 21/02389 (2013.01); H01L 21/02433 (2013.01); H01L 21/304 (2013.01); H01L 29/0657 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A Group-III element nitride semiconductor substrate, comprising:
a first surface; and
a second surface,
wherein the first surface is a minor surface,
wherein the second surface has a second-surface central region and a second-surface outer peripheral region,
wherein the second-surface central region is a minor surface,
wherein the second-surface outer peripheral region is a non-mirror surface, and
wherein the first surface has a surface roughness Ra of 1 nm or less,
wherein the second-surface outer peripheral region has a width of 1 mm or less.