Method for fabricating group III-V compound semiconductor substrate
View Patent ↗Provided is a compound semiconductor substrate fabrication method involving: preparing a base substrate; forming a first buffer layer on the prepared base substrate; forming a semiconductor layer on the first buffer layer; and removing the base substrate.
1. A semiconductor substrate fabrication method comprising:
preparing a base substrate;
forming a first buffer layer on the prepared base substrate;
forming a semiconductor layer on the first buffer layer; and
after forming the semiconductor layer, removing the base substrate such that said semiconductor layer is a final substrate.
2. The method of claim 1 , between forming the semiconductor layer and removing the base substrate, further comprising forming a second buffer layer on the semiconductor layer.
3. The method of claim 1 , wherein the base substrate is formed of a sapphire substrate or a silicon carbide (SiC) substrate.
4. The method of claim 2 , wherein the second buffer layer has the same structure as the first buffer layer.
5. The method of claim 2 , wherein the second buffer layer has a doping concentration profile symmetrical to the first buffer layer.
6. The method of claim 2 , wherein the second buffer layer has a doping concentration profile asymmetrical to the first buffer layer.
7. The method of claim 1 , wherein the first buffer layer is formed of multiple semiconductor material layers having different doping concentrations.
8. The method of claim 7 , wherein forming the multiple semiconductor material layers comprises:
forming a doped semiconductor material layer on the base substrate; and
forming an undoped semiconductor material layer on the doped semiconductor material layer.
9. The method of claim 8 , further comprising on the undoped semiconductor material layer at least once alternately forming the doped semiconductor material layer and the undoped semiconductor material layer.
10. The method of claim 7 , wherein forming the multiple semiconductor material layers comprises:
forming an undoped semiconductor material layer on the base substrate; and
forming a doped semiconductor material layer on the undoped semiconductor material layer.
11. The method of claim 10 , further comprising on the doped semiconductor material layer at least once alternately forming the undoped semiconductor material layer and the doped semiconductor material layer.
12. The method of claim 1 , wherein the first buffer layer is formed of a semiconductor material layer of a gradient doping concentration that increases upwards.
13. The method of claim 12 , wherein forming the semiconductor material layer of the gradient doping concentration that increases upwards comprises:
forming an undoped semiconductor material layer on the base substrate; and
forming a doped semiconductor material layer of a gradient doping concentration that increases upwards, on the undoped semiconductor material layer.
14. The method of claim 13 , wherein the doped semiconductor material layer of the gradient doping concentration that increases upwards comprises multiple semiconductor material layers deposited sequentially, starting with a semiconductor material layer of the lowest doping concentration.
15. The method of claim 2 , wherein the second buffer layer is formed of multiple semiconductor material layers having different doping concentrations.
16. The method of claim 15 , wherein forming the multiple semiconductor material layers comprises:
forming a doped semiconductor material layer on the semiconductor layer; and
forming an undoped semiconductor material layer on the doped semiconductor material layer.
17. The method of claim 16 , further comprising on the undoped semiconductor material layer at least once alternately forming the doped semiconductor material layer and the undoped semiconductor material layer.
18. The method of claim 15 , wherein forming the multiple semiconductor material layers comprises:
forming an undoped semiconductor material layer on the semiconductor layer; and
forming a doped semiconductor material layer on the undoped semiconductor material layer.
19. The method of claim 18 , further comprising on the doped semiconductor material layer at least once alternately forming the undoped semiconductor material layer and the doped semiconductor material layer.
20. The method of claim 2 , wherein the second buffer layer is formed of a semiconductor material layer of a gradient doping concentration that increases upwards.
21. The method of claim 20 , wherein forming the semiconductor material layer of the gradient doping concentration that increases upwards comprises:
forming an undoped semiconductor material layer on the semiconductor layer; and
forming a doped semiconductor material layer of a gradient doping concentration that increases upwards, on the undoped semiconductor material layer.
22. The method of claim 21 , wherein the doped semiconductor material layer of the gradient doping concentration that increases upwards comprises multiple semiconductor material layers deposited sequentially, starting with a semiconductor material layer of the lowest doping concentration.
23. The method of claim 2 , wherein the second buffer layer is formed of a semiconductor material layer of a gradient doping concentration that decreases upwards.
24. The method of claim 23 , wherein forming the semiconductor material layer of the gradient doping concentration that decreases upwards comprises:
forming a doped semiconductor material layer of a gradient doping concentration that decreases upwards, on the semiconductor layer; and
forming a undoped semiconductor material layer on the doped semiconductor material layer.
25. The method of claim 24 , wherein the doped semiconductor material layer of the gradient doping concentration that decreases upwards comprises multiple semiconductor material layers deposited sequentially, starting with a semiconductor material layer of the highest doping concentration.
26. The method of claim 1 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
27. The method of claim 26 , wherein the Group III-V compound semiconductor layer is a silicon-doped GaN layer.
28. The method of claim 4 , wherein the first buffer layer is formed of multiple semiconductor material layers having different doping concentrations.
29. The method of claim 5 , wherein the first buffer layer is formed of multiple semiconductor material layers having different doping concentrations.
30. The method of claim 6 , wherein the first buffer layer is formed of multiple semiconductor material layers having different doping concentrations.
31. The method of claim 4 , wherein the first buffer layer is formed of a semiconductor material layer of a gradient doping concentration that increases upwards.
32. The method of claim 5 , wherein the first buffer layer is formed of a semiconductor material layer of a gradient doping concentration that increases upwards.
33. The method of claim 6 , wherein the first buffer layer is formed of a semiconductor material layer of a gradient doping concentration that increases upwards.
34. The method of claim 2 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
35. The method of claim 15 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
36. The method of claim 16 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
37. The method of claim 18 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
38. The method of claim 20 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
39. The method of claim 23 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.
40. The method of claim 24 , wherein the semiconductor layer is a Group III-V compound semiconductor layer having conductivity.