SiC semiconductor device

Abstract

To provide a SiC semiconductor device that can improve electrical characteristics. [Solution] The SiC semiconductor device includes a SiC chip 2 having a main surface 3, an n-type drift region 8 formed on the surface layer of the main surface 3 and having an impurity concentration adjusted by at least two pentavalent elements, and a p-type impurity region 19 formed within the drift region 8 so as to form a pn junction with the drift region 8.

Claims

1. A SiC chip having a main surface, An n-type drift region formed on the surface of the main surface, having an impurity concentration adjusted by at least two pentavalent elements, A SiC semiconductor device comprising the drift region and a p-type impurity region formed within the drift region so as to form a pn junction.

2. A SiC chip having a main surface, An n-type drift region formed on the surface of the main surface, A SiC semiconductor device comprising: a p-type impurity region formed within the drift region so as to form a pn junction with the drift region, and having an impurity concentration adjusted by a trivalent element other than boron.

3. The SiC semiconductor device according to claim 2, wherein the drift region has an impurity concentration adjusted by at least two pentavalent elements.

4. The drift region has a concentration distribution that increases toward the main surface. The SiC semiconductor device according to any one of claims 1 to 3, wherein the impurity region has a concentration distribution that increases toward the main surface.

5. The SiC semiconductor device according to any one of claims 1 to 4, wherein the drift region contains a pentavalent element other than phosphorus.

6. The SiC semiconductor device according to any one of claims 1 to 5, wherein the impurity region contains at least one trivalent element selected from aluminum, gallium, and indium.

7. The SiC semiconductor device according to any one of claims 1 to 6, wherein the impurity region extends in the thickness direction within the drift region such that it forms a superjunction structure with the drift region and the pn junction.

8. The SiC semiconductor device according to any one of claims 1 to 7, wherein the impurity region crosses the intermediate portion of the drift region with respect to the thickness direction of the drift region.

9. The SiC semiconductor device according to any one of claims 1 to 8, wherein the impurity region is formed with a gap from the bottom of the drift region toward the main surface.

10. The SiC semiconductor device according to any one of claims 1 to 9, wherein the drift region includes a base concentration due to a first impurity which is a pentavalent element, and an additional concentration due to a second impurity which is a pentavalent element other than the first impurity.

11. The drift region is formed at a distance from the main surface and on the surface layer of the main surface, and includes a first region consisting of the base concentration, and a second region formed in the region between the main surface and the first region, consisting of the base concentration and the added concentration. The SiC semiconductor device according to claim 10, wherein the impurity region is formed within the second region so as to form the pn junction with the second region.

12. The SiC semiconductor device according to claim 11, wherein the impurity region is formed within the second region with a gap between it and the first region toward the main surface.

13. The SiC semiconductor device according to any one of claims 10 to 12, wherein the added concentration has a concentration distribution that increases toward the main surface.

14. The SiC semiconductor device according to any one of claims 10 to 13, wherein the base concentration has a substantially constant concentration distribution in the thickness direction.

15. The SiC semiconductor device according to any one of claims 10 to 14, wherein the first impurity is a pentavalent element other than phosphorus.

16. The first impurity is nitrogen, The SiC semiconductor device according to any one of claims 10 to 15, wherein the second impurity is at least one of arsenic and antimony.

17. A SiC chip having a main surface, A p-type drift region is formed on the surface of the main surface and has an impurity concentration adjusted by trivalent elements other than boron, A SiC semiconductor device comprising: an n-type impurity region formed within the drift region so as to form a pn junction with the drift region, and having an impurity concentration adjusted by pentavalent elements other than phosphorus and nitrogen.

18. The drift region has a concentration distribution that increases toward the main surface. The SiC semiconductor device according to claim 17, wherein the impurity region has a concentration distribution that increases toward the main surface.

19. The SiC semiconductor device according to claim 17 or claim 18, wherein the impurity region extends in the thickness direction within the drift region such that it forms a superjunction structure with the drift region and the pn junction.

20. The drift region comprises at least one trivalent element selected from aluminum, gallium, and indium. The SiC semiconductor device according to any one of claims 17 to 19, wherein the impurity region includes at least one of arsenic and antimony.

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