Methods of depositing an alpha-silicon-carbide-containing film at low temperature
View Patent ↗Described methods are useful for depositing a silicon carbide film including Alpha-SiC at low temperatures (e.g., below about 1400° C.), and resulting multi-layer structures and devices. A method includes introducing a chlorinated hydrocarbon gas and a chlorosilicon gas into a reaction chamber, and reacting the chlorinated hydrocarbon gas with the chlorosilicon gas at a temperature of less than about 1400° C. to grow the silicon carbide film. The silicon carbide film so-formed includes Alpha-SiC.
1. A method of depositing a silicon carbide film, the method comprising:
introducing a chlorinated hydrocarbon gas and a chlorosilicon gas into a reaction chamber; and
reacting the chlorinated hydrocarbon gas with the chlorosilicon gas at a temperature of less than about 1400° C. to grow the silicon carbide film on a silicon-based substrate, wherein the silicon carbide film as grown on the silicon-based substrate comprises alpha silicon carbide and has a polytype ratio V α of at least 0.6 and not more than 0.8.
2. The method of claim 1 , wherein the chlorinated hydrocarbon gas comprises at least one chlorinated hydrocarbon gas member selected from the group consisting of dichloroethylene, trichloroethane, and trichloroethylene.
3. The method of claim 1 wherein the chlorosilicon gas comprises at least one chlorosilicon gas member selected from the group consisting of dichlorosilane, silicon tetrachloride, hexachlorodisilane, and trichlorosilane.
4. The method of claim 1 , further comprising controlling a ratio of a flow rate of the chlorinated hydrocarbon gas to a sum of a flow rate of the chlorinated hydrocarbon gas and the chlorosilicon gas to alter a film stress of the silicon carbide film.
5. The method of claim 1 wherein the silicon carbide film exhibits a residual film stress that varies from about 150 MPa to about −375 MPa.
6. The method of claim 1 wherein introducing a chlorinated hydrocarbon gas and a chlorosilicon gas into a reaction chamber comprises flowing the chlorinated hydrocarbon gas and the chlorosilicon gas at respective flow rates such that a ratio of a flow rate of the chlorinated hydrocarbon gas to a sum of a flow rate of the chlorinated hydrocarbon gas and the chlorosilicon gas is about 0.1 to about 0.8.
7. The method of claim 1 wherein introducing a chlorinated hydrocarbon gas and a chlorosilicon gas into a reaction chamber comprises flowing the chlorinated hydrocarbon gas and the chlorosilicon gas at respective flow rates such that a ratio of a flow rate of the chlorinated hydrocarbon gas to a sum of a flow rate of the chlorinated hydrocarbon gas and the chlorosilicon gas is about 0.3 to about 0.5.
8. The method of claim 1 , further comprising controlling a hexagonal silicon carbide polytype ratio in the silicon carbide film by controlling a ratio of a flow rate of the chlorinated hydrocarbon gas to a sum of a flow rate of the chlorinated hydrocarbon gas and the chlorosilicon gas.
9. The method of claim 1 wherein the alpha silicon carbide comprises 6H-SiC and at least one member selected from the group consisting of 4H-SiC, 2H-SiC, and beta silicon carbide.
10. The method of claim 1 wherein the silicon carbide film comprises beta SiC interspersed with the alpha silicon carbide.
11. The method of claim 1 wherein reacting the chlorinated hydrocarbon gas with the chlorosilicon gas at a temperature of less than about 1400° C. to grow the silicon carbide film comprises growing the silicon carbide film homoepitaxially or heteroepitaxially.
12. The method of claim 1 wherein the silicon-based substrate includes an Alpha silicon carbide buffer layer thereon on which the silicon carbide film is grown.
13. The method of claim 1 wherein the silicon-based substrate comprises at least one member of the group consisting of a silicon wafer and a silicon-on-insulator wafer.
14. The method of claim 1 wherein the temperature is in a range of about 800° C. to about 1000° C.
15. The method of claim 1 wherein reacting the chlorinated hydrocarbon gas with the chlorosilicon gas at a temperature of less than about 1400° C. to grow the silicon carbide film is performed at an HCl pressure sufficient to etch a silicon-based substrate on which the silicon carbide film is grown, thereby preferentially inducing the growth of the alpha silicon carbide on the silicon-based substrate instead of beta silicon carbide.
16. The method of claim 1 wherein reacting the chlorinated hydrocarbon gas with the chlorosilicon gas at a temperature of less than about 1400° C. to grow the silicon carbide film is performed via low-pressure chemical vapor deposition.
17. The method of claim 1 , further comprising doping the silicon carbide film with an n-type dopant.
18. A method of depositing a silicon carbide film, the method comprising:
flowing a chlorinated hydrocarbon gas and a chlorosilicon gas at respective flow rates into a low-pressure chemical vapor deposition chamber containing a silicon-based substrate maintained at a temperature of less than about 1400° C.;
wherein a ratio of a flow rate of the chlorinated hydrocarbon gas to a sum of a flow rate of the chlorinated hydrocarbon gas and the chlorosilicon gas is about 0.3 to about 0.5;
wherein the chlorinated hydrocarbon gas comprises at least one chlorinated hydrocarbon gas member selected from the group consisting of dichloroethylene, trichloroethane, and trichloroethylene;
wherein the chlorosilicon gas comprises at least one chlorosilicon gas member selected from the group consisting of dichlorosilane, silicon tetrachloride, hexachlorodisilane, and trichlorosilane; and
reacting the chlorinated hydrocarbon gas and the chlorosilicon gas to grow the silicon carbide film over the silicon-based substrate, wherein the silicon carbide film as grown on the silicon-based substrate comprises alpha silicon carbide and has a polytype ratio V α of at least 0.6 and not more than 0.8.