Method of manufacturing superjunction structure
View Patent ↗The present invention discloses a method of manufacturing superjunction structure, which comprises: step 1, grow an N type epitaxial layer on a substrate having a (100) or (110) oriented surface; step 2, etch the N type epitaxial layer to form trenches therein; step 3, fill the trenches by P type epitaxial growth in the trenches by using a mixture of silicon source gas, halide gas, hydrogen gas, and doping gas. By using the manufacturing method according to the present invention, no void or only small voids are formed in the trenches after trench filling.
1. A method of manufacturing superjunction structure, comprising:
step 1, growing an N type epitaxial layer on a substrate having a (100) or (110) oriented surface;
step 2, etching the N type epitaxial layer to form trenches therein;
step 3, tilling the trenches by P type epitaxial growth in the trenches by using a mixture of silicon source gas, halide gas, hydrogen gas, and doping gas.
2. The method according to claim 1 , wherein the N type epitaxial layer as formed in step 1 has a thickness of 1.0 μm to 100.0 μm.
3. The method according to claim 1 , wherein the trenches as formed in step 2 each has a width of 0.2 μm to 10.0 μm, and a depth of 0.8 μm to 98.0 μm.
4. The method according to claim 1 , wherein the top profile of the trench is in a shape of square, rectangle or stripe.
5. The method according to claim 4 , wherein when the top profile of the trench is square or rectangular:
if the substrate has a (100) oriented surface, the sidewalls of the trench have a crystal orientation of (100);
if the substrate has a (110) oriented surface, the sidewalls of the trench have a crystal orientation of (111);
the bottom profile of the trench is a curved surface with complicated crystal orientations.
6. The method according to claim, 4 , wherein when the profile of the trench is in a shape of stripe:
if the substrate has a (100) oriented surface, the longer sidewalls of the trench have a crystal orientation of (100) while the shorter sidewalls of the trench can be a (100) crystal plane or a plane having multiple crystal orientations or a curved surface;
if the substrate has a (110) oriented surface, the longer sidewalls of the trench have a crystal orientation of (111) while the shorter sidewalls of the trench can be a (111) crystal plane or a plane having multiple crystal orientations or a curved surface;
the bottom profile of the trench is a curved surface with complicated crystal orientations.
7. The method according to claim 1 , wherein the P type epitaxial growth in step 3 is performed under a temperature of 800-1000° C., and a pressure of 0.01 torr to 760 torr.
8. The method according to claim 1 , wherein the silicon source gas is at least one of SiH3Cl, SiH2Cl2, SiHCl3 and SiCl4.
9. The method according to claim 1 , wherein the halide gas is HCl or HF.
10. The method according to claim 1 , wherein the doping gas is boron hydride.
11. The method according to claim 1 , wherein the trenches are tilled by one or more steps of P type epitaxial growth, and before the trenches are completely filled, the opening of the trenches can be enlarged by supplying the halide gas only, or a mixture of the halide gas and the hydrogen gas, or a mixture of the halide gas, the hydrogen gas, and the doping gas.
12. A method of manufacturing superjunction structure, comprising:
step 1, growing a P type epitaxial layer on a substrate having a (100) or (110) oriented surface;
step 2, etching the P type epitaxial layer to form trenches therein;
step 3, filling the trenches by N type epitaxial growth in the trenches by using a mixture of silicon source gas, halide gas, hydrogen gas, and doping gas.
13. The method according to claim 12 , wherein the P type epitaxial layer as formed in step 1 has a thickness of 1.0 μm to 100.0 μm.
14. The method according to claim 12 , wherein the trenches as formed in step 2 each has a width of 0.2 μm to 10.0 μm, and a depth of 0.8 μm to 98.0 μm.
15. The method according to claim 12 , wherein the top profile of the trench is in a shape of square, rectangle or stripe.
16. The method according to claim 15 , wherein when the top profile of the trench is square or rectangular:
if the substrate has a (100) oriented surface, the sidewalls of the trench have a crystal orientation of (100);
if the substrate has a (110) oriented surface, the sidewalls of the trench have a crystal orientation of (111);
the bottom profile of the trench is a curved surface with complicated crystal orientations.
17. The method according to claim 15 , wherein when the profile of the trench is in a shape of stripe:
if the substrate has a (100) oriented surface, the longer sidewalls of the trench have a crystal orientation of (100) while the shorter sidewalls of the trench can be a (100) crystal plane or a plane having multiple crystal orientations or a curved surface;
if the substrate has a (110) oriented surface, the longer sidewalls of the trench have a crystal orientation of (111) while the shorter sidewalls of the trench can be a (111) crystal plane or a plane having multiple crystal orientations or a curved surface;
the bottom profile of the trench is a curved surface with complicated crystal orientations.
18. The method according to claim 12 , wherein the N type epitaxial growth in step 3 is performed under a temperature of 800-1000° C., and a pressure of 0.01 torr to 760 torr.
19. The method according to claim 12 , wherein the silicon source gas is at least one of SiH3Cl, SiH2Cl2, SiHCl3 and SiCl4.
20. The method according to claim wherein the halide gas is HCl or HF.
21. The method according to claim 12 , wherein the doping gas is at least one of phosphine and arsenic hydride.
22. The method according to claim 12 , wherein the trenches are tilled by one or more steps of N type epitaxial growth, and before the trenches are completely filled, the opening of the trenches can be enlarged by supplying the halide gas only, or a mixture of the halide gas and the hydrogen gas, or a mixture of the halide gas, the hydrogen gas, and the doping gas.