Solid solution wide bandgap semiconductor materials
View Patent ↗A substrate and method for growing a semi-conductive crystal on an alloy film such as (AIN) x (SiC) (1-x) without any buffer layer is disclosed. The (AIN) x (SiC) (1-x) alloy film can be formed on a SiC substrate by a vapor deposition process using AlN and SiC powder as starting materials. The (AIN) x (SiC) (1-x) alloy film provides a better lattice match for GaN or SiC epitaxial growth and reduces defects in epitaxially grown GaN with better lattice match and chemistry.
1. A method for producing a semiconductor crystal, comprising
depositing a semiconductor material on an alloy film by a vapor deposition method,
wherein the semiconductor material is selected from the group consisting of nitride, carbide and diamond, and wherein the alloy is (AIN) x (SiC) (1-x) or Si x Ge (1-x) C, where 0<x<1.
2. The method of claim 1 , wherein the vapor deposition method is selected from the group consisting of PVT, APVT, MOCVD and CVD.
3. The method of claim 2 , wherein the semiconductor material comprises GaN and the alloy comprises (AIN) x (SiC) (1-x) , and wherein the vapor deposition method is PVT.
4. The method of claim 1 , further comprising the step of:
forming the alloy film by a vapor deposition method on a substrate prior to depositing the semiconductor material.
5. The method of claim 4 , wherein the substrate is selected from the group consisting of carbon, silicon and SiC.
6. The method of claim 5 , wherein the substrate comprises SiC.
7. The method of claim 6 , wherein the substrate comprises a on-axis 6H—SiC.
8. The method of claim 5 , wherein the substrate comprises SiC and the alloy film comprises (AIN) x (SiC) (1-x) , formed by PVT, APVT, MOCVD or CVD.
9. The method of claim 4 , further comprising the step of:
doping the substrate prior to forming the alloy film on the substrate.
10. The method of claim 9 , wherein the substrate comprises SiC and is doped with ammonia or trimethyl aluminum in an MOCVD process.
11. The method of claim 4 , further comprising the step of:
treating the substrate with hexamethyldisilizane and ammonia prior to forming the alloy film on the substrate.
12. The method of claim 1 , wherein the semiconductor material comprises SiC and the alloy comprises (AIN) x (SiC) (1-x) .
13. The method of claim 1 , wherein the semiconductor material comprises diamond and the alloy comprises (AIN) x (SiC) (1-x) .
14. A method for producing a AlN-rich (AlN) x (SiC) (1-x) alloy film on a substrate, comprising:
depositing AlN and SiC on a substrate to form an (AlN) x (SiC) (1-x) alloy in a PVT process under a background pressure of less than 100 torr using AlN and SiC powder as starting materials.
15. The method of claim 14 , wherein the substrate comprises doped SiC.
16. A method for producing a SiC-rich (AlN) x (SiC) (1-x) alloy film on a substrate, comprising:
depositing AlN and SiC on a substrate to form an (AlN) x (SiC) (1-x) alloy in a PVT process under a background pressure of 400-500 torr using AlN and SiC powder as starting materials.
17. The method of claim 16 , wherein the substrate comprises doped SiC.