Method and apparatus for producing ultra-thin graphitic layers
In a method of producing ultra-thin graphitic layers, a carbide crystal is placed into a graphitic enclosure. The carbide crystal and the graphitic enclosure are placed into a chamber. The carbide crystal and the graphitic enclosure are subjected to a predetermined environment. Once the predetermined environment is established, the carbide crystal and the graphitic enclosure are heated to a first temperature for a predetermined period of time sufficient to cause at least one non-carbon element to evaporate from a crystal face of the carbide crystal so as to form at least one graphitic layer on the crystal face of the carbide crystal.
1. A method of producing ultra-thin graphitic layers, comprising the actions of:
a. placing a carbide crystal into a graphitic enclosure;
b. placing the carbide crystal and the graphitic enclosure into a chamber;
c. subjecting the carbide crystal and the graphitic enclosure to a predetermined environment;
d. once the predetermined environment is established, heating the carbide crystal and the graphitic enclosure to a first temperature for a predetermined period of time sufficient to cause at least one non-carbon element to evaporate from a crystal face of the carbide crystal so as to form at least one graphitic layer on the crystal face of the carbide crystal; and
e. reacting residual gaseous reactants in the graphitic enclosure that would act as impurities in the ultra-thin graphitic layers with the graphitic enclosure so as to transform such residual gaseous reactants into substances that will not add impurities to the ultra-thin graphitic layers; and
f. placing the carbide crystal and the graphitic enclosure into a conductive receptacle, wherein the heating action includes inductively heating the conductive receptacle by applying radio frequency radiation to the conductive receptacle.
2. The method of claim 1 , wherein the conductive receptacle comprises molybdenum.
3. The method of claim 1 , further comprising the action of cleaning and flattening the crystal face of the carbide crystal.
4. The method of claim 3 , wherein the cleaning and flattening action comprises the action of hydrogen etching the crystal face.
5. The method of claim 1 , wherein the chamber comprises a vacuum chamber and wherein the predetermined environment comprises a vacuum.
6. The method of claim 1 , wherein the subjecting action comprises evacuating the chamber to a predetermined vacuum having a pressure that is less than 10 −2 Torr.
7. The method of claim 1 , wherein the first temperature is in a range from 1200° C. to 1700° C.
8. The method of claim 1 , further comprising the action of introducing an inert gas into the chamber during the heating action.
9. The method of claim 8 , wherein the inert gas comprises helium.
10. The method of claim 1 , wherein the carbide crystal comprises silicon carbide and wherein the non-carbon element comprises silicon.
11. The method of claim 1 , wherein the chamber comprises a material selected from a group consisting of: quartz, alumina and combinations thereof.
12. The method of claim 1 , further comprising the actions of:
a. placing the carbide crystal and the graphitic enclosure in a second zone of the chamber that is heated to a second temperature, different from the first temperature; and
b. moving the carbide crystal and the graphitic enclosure into a first zone of the chamber, spaced apart from the second zone, that is heated to the first temperature.
13. The method of claim 12 , further comprising the action of moving the carbide crystal and the graphitic enclosure into a third zone of the chamber, spaced apart from the first zone and the second zone that is heated to a third temperature, different from the first temperature and the second temperature.