US 12,446,263 B2
Nitride semiconductor device
Norikazu Ito, Kyoto (JP); Taketoshi Tanaka, Kyoto (JP); and Ken Nakahara, Kyoto (JP)
Assigned to ROHM CO., LTD., Kyoto (JP)
Appl. No. 17/906,808
Filed by ROHM CO., LTD., Kyoto (JP)
PCT Filed Apr. 14, 2021, PCT No. PCT/JP2021/015487
§ 371(c)(1), (2) Date Sep. 20, 2022,
PCT Pub. No. WO2021/215336, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 2020-076664 (JP), filed on Apr. 23, 2020.
Prior Publication US 2023/0114315 A1, Apr. 13, 2023
Int. Cl. H10D 30/47 (2025.01); H10D 30/67 (2025.01); H10D 62/824 (2025.01); H10D 62/85 (2025.01); H10D 64/64 (2025.01)
CPC H10D 30/675 (2025.01) [H10D 30/475 (2025.01); H10D 30/4755 (2025.01); H10D 30/6738 (2025.01); H10D 62/824 (2025.01); H10D 62/85 (2025.01); H10D 62/8503 (2025.01); H10D 64/64 (2025.01)] 11 Claims
OG exemplary drawing
 
1. A nitride semiconductor device comprising:
an electron transit layer;
an electron supply layer that is formed on the electron transit layer;
a gate layer that is formed on the electron supply layer and includes an Al1-XGaXN (0<X<1) based material containing a first impurity;
a gate electrode that is formed on the gate layer and is in Schottky junction with the gate layer; and
a source electrode and a drain electrode that are electrically connected to the electron supply layer, wherein
the electron transit layer includes a GaN based material,
the electron supply layer includes an Al1-XGaXN (0<X<1) based material,
the gate layer has an Al composition ratio that is less than an Al composition ratio of the electron supply layer, and
the gate layer includes a first portion that is relatively low in Al composition ratio and a second portion that is formed at an opposite side of the electron supply layer with respect to the first portion and has an Al composition ratio relatively higher than that of the first portion wherein an average Al composition ratio of the first portion and the second portion is less than the Al composition ratio of the electron supply layer.