SiC epitaxial wafer and method for manufacturing SIC epitaxial wafer
A SiC epitaxial wafer of the present invention includes a SiC single crystal substrate, and a high concentration layer that is provided on the SiC single crystal substrate and has an average value of an n-type doping concentration of 1×10 18 /cm 3 or more and 1×10 19 /cm 3 or less, and in-plane uniformity of the doping concentration of 30% or less.
1. A SiC epitaxial wafer comprising:
a SiC single crystal substrate; and
a high concentration layer that is provided on the SiC single crystal substrate and has an average value of an n-type doping concentration of 1×10 18 /cm 3 or more and 1×10 19 /cm 3 or less, and in-plane uniformity of the n-type doping concentration of 30% or less,
wherein the high concentration layer is doped with nitrogen, and
the in-plane uniformity is obtained from
an absolute value of (a maximum value of the n-type doping concentration−a minimum value of the n-type doping concentration)/an average value of the n-type doping concentration.
2. The SiC epitaxial wafer according claim 1 ,
wherein the high concentration layer is a buffer layer, and
a drift layer having an average value of a doping concentration lower than an average value of the doping concentration of the buffer layer is provided on the buffer layer.
3. The SiC epitaxial wafer according to claim 1 , wherein the in-plane uniformity of the high concentration layer is 20% or less.
4. The SiC epitaxial wafer according to claim 1 , wherein the in-plane uniformity of the high concentration layer is 10% or less.
5. The SiC epitaxial wafer according to claim 1 , wherein a diameter of the wafer is 150 mm or more.
6. The SiC epitaxial wafer according to claim 2 , wherein the in-plane uniformity of the high concentration layer is 20% or less.
7. The SiC epitaxial wafer according to claim 2 , wherein the in-plane uniformity of the high concentration layer is 10% or less.
8. The SiC epitaxial wafer according to claim 3 , wherein the in-plane uniformity of the high concentration layer is 10% or less.
9. The SiC epitaxial wafer according to claim 6 , wherein the in-plane uniformity of the high concentration layer is 10% or less.
10. The SiC epitaxial wafer according to claim 2 , wherein a diameter of the wafer is 150 mm or more.
11. The SiC epitaxial wafer according to claim 3 , wherein a diameter of the wafer is 150 mm or more.
12. The SiC epitaxial wafer according to claim 4 , wherein a diameter of the wafer is 150 mm or more.
13. The SiC epitaxial wafer according to claim 6 , wherein a diameter of the wafer is 150 mm or more.
14. The SiC epitaxial wafer according to claim 7 , wherein a diameter of the wafer is 150 mm or more.
15. The SiC epitaxial wafer according to claim 8 , wherein a diameter of the wafer is 150 mm or more.
16. The SiC epitaxial wafer according to claim 9 , wherein a diameter of the wafer is 150 mm or more.
17. The SiC epitaxial wafer according to claim 1 , wherein the high concentration layer has the average value of the n-type doping concentration of 1.2×10 18 /cm 3 or more and 1×10 19 /cm 3 or less.
18. The SiC epitaxial wafer according to claim 1 , wherein the high concentration layer has the average value of the n-type doping concentration of 1.5×10 18 /cm 3 or more and 1×10 19 /cm 3 or less.
19. The SiC epitaxial wafer according to claim 1 , wherein the high concentration layer has the average value of the n-type doping concentration of 2×10 18 /cm 3 or more and 1×10 19 /cm 3 or less.
20. The SiC epitaxial wafer according to claim 1 , wherein the high concentration layer has the average value of the n-type doping concentration of 3×10 18 /cm 3 or more and 1×10 19 /cm 3 or less.
21. The SiC epitaxial wafer according to claim 1 , wherein the high concentration layer has the average value of the n-type doping concentration of 5×10 18 /cm 3 or more and 1×10 19 /cm 3 or less.