Method for chemical vapor deposition (CVD) with showerhead and method thereof
Disclosed is a method of chemical vapor deposition (CVD). The method provides for use of a showerhead through which a source material gas including a reactive gas of at least one kind and a purge gas is injected over a substrate located in a reaction chamber to deposit a film on the substrate. The showerhead has reactive gas outlets surrounded by purge gas outlets. The bottom surface of the showerhead is spaced apart from the substrate by a predetermined distance. Reactive gases of different kinds are injected into compartments formed inside the showerhead so that each compartment of the showerhead is filled with the reactive gas of only one kind, and a purge gas of the source material gas is supplied into another compartment formed inside the showerhead. The reactive gas and the purge gas are discharged through the reactive gas outlets and purge gas outlets. Preferably, there are more purge gas outlets than reactive gas outlets.
1. A method of chemical vapor deposition (CVD) comprising:
providing a showerhead through which a source material gas including a reactive gas of at least one kind and a purge gas is injected over a substrate located in a reaction chamber to deposit a film on the substrate, wherein the showerhead has a plurality of reactive gas outlets and each is surrounded by a corresponding purge gas outlet;
disposing the showerhead in such a way that the bottom surface of the showerhead is spaced apart from the substrate by a predetermined distance;
supplying a reactive gas of the source material gas into the showerhead, wherein reactive gases of different kinds are injected into compartments formed inside the showerhead so that each compartment of the showerhead is filled with the reactive gas of only one kind and a purge gas of the source material gas is supplied into another compartment formed inside the showerhead; and
discharging the reactive gas and the purge gas through the plurality of reactive gas outlets and the plurality of purge gas outlets formed on the bottom surface of the showerhead wherein the reactive gas is discharged from the individual reactive gas outlets and the discharged reactive gas is surrounded by discharged purge gas, and further wherein the discharged reactive gas and purge gas are discharged in the same direction toward the substrate.
2. A method of chemical vapor deposition (CVD) according to claim 1 , wherein in the discharge step, a flow of the reactive gas injected from the reactive gas outlets is surrounded by a flow of the purge gas injected from one part of the purge gas outlets which surround the reactive gas outlet, and the other part of the purge gas outlets which do not surround the reactive gas outlets discharge only the purge gas.
3. A method of chemical vapor deposition (CVD) according to claim 1 , wherein the purge gas is at least one selected from the group consisting of Ar, N 2 , He, H 2 and O 2 .
4. A method of chemical vapor deposition (CVD) according to claim 1 , wherein the reactive gas is a pure vapor by heating metal-organic compounds at liquid phase.
5. A method of chemical vapor deposition (CVD) according to claim 1 , wherein the reactive gas is a mixture of a vaporized material containing compositions of the film deposited and a carrier gas for vaporizing said material in an evaporator.
6. A method of chemical vapor deposition (CVD) according to claim 1 , further comprising the step of cooling the showerhead by supplying a refrigerant into a cooling jacket surrounding the showerhead, then discharging the refrigerant from the reaction chamber.