Semiconductor device, semiconductor device manufacturing method, inverter circuit, driver device, vehicle, and elevator
This semiconductor device according to an embodiment includes: a silicon carbide layer; a gate electrode; a silicon oxide layer between the silicon carbide layer and the gate electrode; and a region between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration not less than 1×10 21 cm −3 . A nitrogen concentration distribution in the silicon carbide layer, the silicon oxide layer, and the region has its peak in the region, and a state density Z 1/2 in a portion is not more than 1×10 11 cm −3 . The portion is within 100 nm from the silicon oxide layer toward the silicon carbide layer. A nitrogen concentration and a carbon concentration in a position 1 nm from the peak toward the silicon oxide layer is not more than 1×10 18 cm −3 , and a nitrogen concentration in a position 1 nm from the peak toward the silicon carbide layer is not more than 1×10 18 cm −3 .
1. A semiconductor device, comprising:
a silicon carbide layer;
a gate electrode;
a silicon oxide layer disposed between the silicon carbide layer and the gate electrode; and
a region disposed between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration equal to or more than 1×10 21 cm −3 ,
wherein a nitrogen concentration distribution in the silicon carbide layer, the silicon oxide layer, and the region has its peak in the region, and
a state density Z 1/2 measured using deep level transient spectroscopy (DLTS) in a portion is equal to or less than 1×10 11 cm −3 , the portion is disposed between the silicon oxide layer and a first position spaced apart by 100 nm from the silicon oxide layer toward the silicon carbide layer,
a nitrogen concentration in a second position spaced apart by 1 nm from the peak toward the silicon oxide layer is equal to or less than 1×10 18 cm −3 , a carbon concentration in the second position is equal to or less than 1×10 18 cm −3 , and
a nitrogen concentration in a third position spaced apart by 1 nm from the peak toward the silicon carbide layer is equal to or less than 1×10 18 cm −3 .
2. The device according to claim 1 ,
wherein a nitrogen concentration at the peak is equal to or more than 1×10 22 cm −3 .
3. The device according to claim 1 ,
wherein the silicon carbide layer includes a first silicon carbide region of n-type, and a second silicon carbide region of p-type disposed between the first silicon carbide region and the silicon oxide layer, and
the portion is disposed in the second silicon carbide region.
4. The device according to claim 1 ,
wherein the Hall mobility of electrons in the portion is equal to or more than 200 cm 2 /V·s.
5. The device according to claim 1 ,
wherein a quantity of nitrogen atoms bonded to the four silicon atoms in a fourth position spaced apart by 5 nm from the silicon oxide layer toward the silicon carbide layer is equal to or more than 80% and equal to or less than 120% of a quantity of nitrogen atoms bonded to the four silicon atoms in a fifth position spaced apart by 5 μm from the silicon oxide layer toward the silicon carbide layer.
6. An inverter circuit, comprising:
the semiconductor device according to claim 1 .
7. A driver device, comprising:
the semiconductor device according to claim 1 .
8. A vehicle, comprising:
the semiconductor device according to claim 1 .
9. An elevator, comprising:
the semiconductor device according to claim 1 .