Fabrication method of nitride semiconductors and nitride semiconductor structure fabricated thereby
View Patent ↗Disclosed is a method of fabricating nitride semiconductors in a MOCVD reactor. GaN is first deposited on an inner wall of the MOCVD reactor, and a sapphire substrate is loaded into the MOCVD reactor. The sapphire substrate is heated and etching gas is injected into the MOCVD reactor. NH 3 gas is injected into the MOCVD reactor to nitrify the surface of the sapphire substrate. A nitride semiconductor layer is grown on the nitrified sapphire substrate. By surface-reforming the sapphire substrate and then growing the nitride semiconductor layer on the surface-reformed sapphire substrate via MOCVD without formation of a low temperature buffer layer, an excellent nitride semiconductor structure can be realized. In this circumstance, the nitride semiconductor layer for example of GaN can be grown effectively on the surface-treated sapphire substrate because GaN deposition occurs on the sapphire substrate while it is etched.
1. A method of fabricating nitride semiconductors in a Metal-Organic Chemical Vapor Deposition (MOCVD) reactor, the method comprising the following steps of:
(a) depositing GaN on an inner wall of the MOCVD reactor,
(b) loading a sapphire substrate into the MOCVD reactor;
(c) heating the sapphire substrate and injecting etching gas into the MOCVD reactor; and
(d) injecting NH 3 gas into the MOCVD reactor to nitrify the surface of the sapphire substrate.
2. The method of fabricating nitride semiconductors according to claim 1 , wherein the step (c) irregularly etches the surface of the sapphire and re-deposits the GaN onto the surface of the sapphire from the inner wall of the MOCVD reactor.
3. The method of fabricating nitride semiconductors according to claim 2 , wherein the GaN re-deposited onto the sapphire is amorphous or polycrystalline.
4. The method of fabricating nitride semiconductors according to claim 1 , further comprising the step of growing a nitride semiconductor layer on the nitrified surface of the sapphire substrate after the step (d).
5. The method of fabricating nitride semiconductors according to claim 1 , wherein the sapphire substrate is replaced by one selected from a group including a silicon carbide (SiC) substrate, an oxide substrate and carbide substrate.
6. The method of fabricating nitride semiconductors according to claim 1 , wherein the NH 3 gas is replaced by one selected from a group consisting of tertiary-butylamine (N(C 4 H 9 )H 2 ), phenylhydrazine (C 6 H 8 N 2 ) and dimethylhydrazine (C 2 H 8 N 2 ).