US 11,955,520 B2
Nitride semiconductor with multiple nitride regions of different impurity concentrations, wafer, semiconductor device and method for manufacturing the same
Toshiki Hikosaka, Kawasaki (JP); Hajime Nago, Yokohama (JP); Jumpei Tajima, Mitaka (JP); and Shinya Nunoue, Ichikawa (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Jul. 8, 2021, as Appl. No. 17/305,470.
Claims priority of application No. 2020-205601 (JP), filed on Dec. 11, 2020.
Prior Publication US 2022/0190119 A1, Jun. 16, 2022
Int. Cl. H01L 29/20 (2006.01); H01L 21/02 (2006.01); H01L 29/15 (2006.01); H01L 29/207 (2006.01); H01L 29/36 (2006.01); H01L 29/778 (2006.01)
CPC H01L 29/2003 (2013.01) [H01L 21/0254 (2013.01); H01L 21/02576 (2013.01); H01L 21/0262 (2013.01); H01L 29/155 (2013.01); H01L 29/207 (2013.01); H01L 29/36 (2013.01); H01L 29/7786 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A nitride semiconductor, comprising:
a nitride member,
the nitride member including:
a first nitride region including Alx1Ga1-x1N (0<x1≤1);
a second nitride region including Alx2Ga1-x2N (0<x2<1, x2<x1); and
a third nitride region, the second nitride region being between the first nitride region and the third nitride region, the third nitride region including Al, Ga, and N, the third nitride region not including carbon, alternatively a third carbon concentration in the third nitride region being lower than a second carbon concentration in the second nitride region,
wherein
the third nitride region includes a plurality of first regions and a plurality of second regions,
in a first direction from the first nitride region to second nitride region, one of the plurality of first regions is between one of the plurality of second regions and another one of the plurality of second regions, the one of the plurality of second regions is between the one of the plurality of first regions and another one of the plurality of first regions,
the first region includes Aly1Ga1-y1N (0<y1≤1), and
the second region includes Aly2Ga1-y2N (0≤y2<y1),
a first region thickness along the first direction of each of the plurality of first regions is thinner than a second nitride region thickness along the first direction of the second nitride region, and
a second region thickness along the first direction of each of the plurality of second regions is thinner than the second nitride region thickness.