Semiconductor device
A semiconductor device having a trench gate structure is provided. A semiconductor device is provided, including: a first-conductivity-type drift region provided in a semiconductor substrate; a first-conductivity-type accumulation region provided above the drift region and having a higher doping concentration than the drift region; a second-conductivity-type base region provided above the accumulation region; and an electric-field relaxation layer provided between the accumulation region and the base region and having a lower doping concentration than the accumulation region. The electric-field relaxation layer may include a first-conductivity-type region including a region having a same doping concentration as the drift region.
1. A semiconductor device comprising:
a first-conductivity-type drift region provided in a semiconductor substrate;
a first-conductivity-type accumulation region provided above the drift region and having a higher doping concentration than the drift region;
a second-conductivity-type base region provided above the accumulation region; and
an electric-field relaxation layer provided between the accumulation region and the base region and having a lower doping concentration than the accumulation region, wherein
a thickness of the electric-field relaxation layer is equal to or smaller than a thickness of the accumulation region.
2. The semiconductor device according to claim 1 , wherein the electric-field relaxation layer comprises a first-conductivity-type region including a region having a same doping concentration as the drift region.
3. The semiconductor device according to claim 2 , wherein in the electric-field relaxation layer, the region having the same doping concentration as the drift region extends over a length of 0.5 μm or more in a depth direction of the semiconductor substrate.
4. The semiconductor device according to claim 1 , wherein a doping concentration of the electric-field relaxation layer is lower by one or more orders of magnitude than a peak in doping concentration of the accumulation region.
5. The semiconductor device according to claim 1 , wherein a doping concentration of the electric-field relaxation layer is lower than a peak in doping concentration of the base region.
6. The semiconductor device according to claim 1 , wherein the thickness of the electric-field relaxation layer is 0.5 μm or more and less than 1.5 μm.
7. A semiconductor device comprising:
a first-conductivity-type drift region provided in a semiconductor substrate;
a first-conductivity-type accumulation region provided above the drift region and having a higher doping concentration than the drift region;
a second-conductivity-type base region provided above the accumulation region; and
an electric-field relaxation layer provided between the accumulation region and the base region and having a lower doping concentration than the accumulation region,
wherein a thickness of the electric-field relaxation layer is 0.5 μm or more and less than 1.5 μm.
8. The semiconductor device according to claim 7 , wherein the electric-field relaxation layer comprises a first-conductivity-type region including a region having a same doping concentration as the drift region.
9. The semiconductor device according to claim 8 , wherein in the electric-field relaxation layer, the region having the same doping concentration as the drift region extends over a length of 0.5 μm or more in a depth direction of the semiconductor substrate.
10. The semiconductor device according to claim 7 , wherein a doping concentration of the electric-field relaxation layer is lower by one or more orders of magnitude than a peak in doping concentration of the accumulation region.
11. The semiconductor device according to claim 7 , wherein a doping concentration of the electric-field relaxation layer is lower than a peak in doping concentration of the base region.
12. The semiconductor device according to claim 7 , wherein the thickness of the electric-field relaxation layer is equal to or smaller than a thickness of the accumulation region.
13. A semiconductor device comprising:
a first-conductivity-type drift region provided in a semiconductor substrate;
a first-conductivity-type accumulation region provided above the drift region and having a higher doping concentration than the drift region;
a second-conductivity-type base region provided above the accumulation region; and
an electric-field relaxation layer provided between the accumulation region and the base region and having a lower doping concentration than the accumulation region, wherein
a peak of a doping concentration of the accumulation region is greater than a peak of a doping concentration of the base region.
14. The semiconductor device according to claim 13 , wherein the electric-field relaxation layer comprises a first-conductivity-type region including a region having a same doping concentration as the drift region.
15. The semiconductor device according to claim 14 , wherein in the electric-field relaxation layer, the region having the same doping concentration as the drift region extends over a length of 0.5 μm or more in a depth direction of the semiconductor substrate.
16. The semiconductor device according to claim 13 , wherein a doping concentration of the electric-field relaxation layer is lower by one or more orders of magnitude than a peak in doping concentration of the accumulation region.
17. The semiconductor device according to claim 13 , wherein a doping concentration of the electric-field relaxation layer is lower than a peak in doping concentration of the base region.
18. The semiconductor device according to claim 13 , wherein a thickness of the electric-field relaxation layer is equal to or smaller than a thickness of the accumulation region.
19. The semiconductor device according to claim 13 , wherein a thickness of the electric-field relaxation layer is 0.5 μm or more and less than 1.5 μm.