초록 ▼

An apparatus and methods for forming a diamond film, are provided. An example of an apparatus for forming a diamond film includes an electrodeless microwave plasma reactor having a microwave plasma chamber configured to contain a substrate and to contain a reactant gas excited by microwaves to gener

An apparatus and methods for forming a diamond film, are provided. An example of an apparatus for forming a diamond film includes an electrodeless microwave plasma reactor having a microwave plasma chamber configured to contain a substrate and to contain a reactant gas excited by microwaves to generate a microwave plasma discharge. Gas injection ports extend through an outer wall of the plasma chamber at a location upstream of the plasma discharge and above the substrate. Gas jet injection nozzles interface with the gas injection ports and are configured to form a directed gas stream of reactant gas having sufficient kinetic energy to disturb a boundary layer above an operational surface of the substrate to establish a convective transfer of the film material to the operational surface of the substrate.

대표청구항 ▼

1. A method for forming diamond film, the method comprising the following steps to enhance growth rate of a diamond film on an operational surface of a substrate while maintaining substantial uniformity of the film: configuring each of a plurality of directed gas jet injection nozzles of an electrod

1. A method for forming diamond film, the method comprising the following steps to enhance growth rate of a diamond film on an operational surface of a substrate while maintaining substantial uniformity of the film: configuring each of a plurality of directed gas jet injection nozzles of an electrodeless microwave plasma reactor to create a directed gas stream of reactant gas within a microwave plasma chamber of the electrodeless microwave plasma reactor;orienting at least three of the plurality of directed gas jet injection nozzles so that a longitudinal axis of the each gas jet injection nozzle extends to a location on the proximal surface of the substrate of between approximately 9 and 13 percent of a length of the proximal surface of the substrate; andorienting each directed gas stream to interact with at least one other directed gas stream and with a microwave plasma discharge when generated within the microwave plasma chamber. 2. A method as defined in claim 1, further comprising the step of: imparting substantial kinetic energy to each directed gas stream sufficient to substantially disturb a boundary layer above the substrate, intensifying and flattening a hemispherical shape of the microwave plasma discharge to thereby substantially increase an impingement rate of reactant material on the operational surface of the substrate, the increased impingement rate resulting in a substantial increase in growth rate of deposited film material. 3. A method as defined in claim 1, wherein the step of orienting each directed gas stream includes the steps of: configuring a plurality of reactant gas injection ports to each receive a separate one of the plurality of directed gas jet injection nozzles, each of the plurality of reactant gas injection ports extending through a proximal end portion of the microwave plasma chamber at a location substantially upstream of a location of the microwave plasma discharge when generated and above the operational surface of the substrate when operably positioned within the microwave plasma chamber,interfacing each of the at least three gas jet injection nozzles with a corresponding at least three of the plurality of reactant gas injection ports spaced substantially evenly apart within a same plane, andorienting each of the at least three gas jet injection nozzles at a substantially same acute angle with respect to the operational surface of the substrate to improve uniformity and manage a shape of the microwave plasma discharge. 4. A method as defined in claim 3, wherein the step of configuring a plurality of reactant gas injection ports includes modifying a size of each of the at least three existing gas injection ports;wherein the plurality of directed gas jet injection nozzles includes at least a fourth gas jet injection nozzles; andwherein the step of orienting each directed gas stream further includes the steps of: interfacing the at least a fourth gas injection nozzle with a corresponding one of the plurality of reactant gas injection ports positioned upstream of the microwave plasma discharge and substantially above a center of the operational surface of the substrate when the substrate is operably positioned within the microwave plasma chamber, andorienting the at least a fourth gas jet injection nozzle at an angle approximately normal to the operational surface of the substrate. 5. A method as defined in claim 4, wherein the diamond film is an optical grade diamond film;wherein the growth rate of diamond film on the substrate is between approximately 7-9 microns per hour; andwherein the step of configuring the electrodeless microwave plasma reactor includes configuring the reactor so that the diamond film produced by the reactor has a thickness of between approximately 100 and 180 microns at an optical quality characterized by an absorption of less than 5% at a wavelength of between approximately 7.9 and 10.6 micrometers and an absorption of less than 10% at a wavelength of between approximately 10.6 and 12.0 micrometers. 6. A method as defined in claim 5, further comprising the step of: controlling a combination of a flow rate of gas entering the microwave plasma chamber, a velocity of gas injected from each of the plurality of directed gas jet injection nozzles into the microwave plasma chamber, a temperature within the chamber, and a pressure within the chamber to thereby control a shape of the microwave plasma discharge and a concentration of reactant species in close proximity to the operational surface of the substrate. 7. A method for forming diamond film, the method comprising the steps of: configuring a plurality of directed gas jet injection nozzles of an electrodeless microwave plasma reactor to create a directed gas stream of reactant gas within a microwave plasma chamber of the electrodeless microwave plasma reactor, each of the plurality of directed gas jet injection nozzles configured to form a directed gas stream of reactant gas;positioning at least three of the plurality of directed gas jet injection nozzles at an angle of between approximately 50 and 60 degrees to a proximal surface of an operational surface of a substrate for growing film so that a longitudinal axis of the each gas jet injection nozzle extends to a location on the proximal surface of the substrate of between approximately 9 and 13 percent of a length of the proximal surface of the substrate;orienting each directed gas stream to interact with at least one other directed gas stream and with the microwave plasma discharge when generated within the microwave plasma chamber to thereby enhance growth rate of the film on the operational surface of a substrate while maintaining substantial uniformity of the film;imparting substantial kinetic energy to the directed gas stream sufficient to disturb a boundary layer above the substrate, intensifying and flattening a hemispherical shape of the microwave plasma discharge, to thereby increase an impingement rate of reactant material on the operational surface of the substrate, the increased impingement rate resulting in a substantial increase in growth rate of deposited film material;configuring a controller to control a flow rate of gas entering the microwave plasma chamber, a velocity of gas exiting each directed gas jet nozzle, and a pressure within the chamber to thereby control a shape of the microwave plasma discharge and a deposition rate of the reactant material, and to monitor temperature within the chamber;positioning a mass flow meter to meter the reactant gas entering each of the plurality of directed gas jet nozzles and in communication with the controller to provide mass flow rate data thereto;positioning a pyrometer to measure temperature within the microwave plasma chamber during operation of the electrodeless microwave plasma reactor and in communication with the controller to provide temperature data thereto; andmaintaining temperature uniformity on at least one of the diamond film and substrate temperature during operation of the electrodeless microwave plasma reactor. 8. A method as defined in claim 7, further comprising the step of: positioning a microwave generator assembly in communication with the microwave plasma chamber to generate the microwave plasma discharge at a location of the substrate within the microwave plasma chamber. 9. A method as defined in claim 8, wherein the plurality of directed gas jet nozzles are each interfaced with a respective one of a plurality of reactant gas injection ports in a proximal end portion of the microwave plasma chamber, and oriented to interact with each other at a location above the operational surface of the substrate when the substrate is operably positioned within the microwave plasma chamber; andwherein the method further comprises the step of positioning a microwave generator assembly waveguide at a distal end portion of the microwave plasma chamber to thereby form the microwave plasma discharge at the location of the substrate, downstream of the plurality of directed gas jet nozzles. 10. A method as defined in claim 7, wherein the plurality of directed gas jet nozzles include at least three gas jet injection nozzles, wherein each of the at least three gas jet injection nozzles have a length established at between approximately 0.1 and 4.0 inches, and wherein each of the at least three gas jet injection nozzles have an inner aperture diameter established at between approximately 0.030 and 0.04 inches, the method further comprising the steps of: interfacing each of the at least three gas jet injection nozzles with a respective one of a plurality of reactant gas injection ports in a proximal end portion of the microwave plasma chamber; andorienting each of the at least three gas jet injection nozzles to interact with each other at a location above an operational surface of the substrate, to include spacing the at least three gas jet injection nozzles substantially evenly apart within a same plane and oriented at a substantially same acute angle with respect to a proximal surface of the substrate of between approximately 50 and 60 degrees to the proximal surface of the substrate to thereby provide for a growth rate of diamond film on the substrate of between approximately 5 and 10 microns per hour. 11. A method as defined in claim 10, further comprising the steps of: establishing the velocity of gas exiting each gas jet injection nozzle at between approximately 10 and 300 meters per second;establishing an operational flow rate of the reactant gas entering the microwave plasma chamber at between approximately 0.3 and 1 standard liters per minute;establishing a composition of the reactant gas at between approximately 0.5 and 4 percent carbon precursor;establishing an operational temperature of the substrate at between approximately 780 and 1200 degrees Centigrade; andestablishing an operational pressure within the microwave plasma chamber at between approximately 50 and 200 Torr. 12. A method for forming diamond film, the method comprising the steps of: configuring at least one directed gas jet injection nozzle of an electrodeless microwave plasma reactor to create a directed gas stream of reactant gas within a microwave plasma chamber of the electrodeless microwave plasma reactor, wherein the at least one directed gas jet nozzle includes a plurality of directed gas jet nozzles, each configured to form a directed gas stream of reactant gas, wherein the plurality of directed gas jet nozzles include at least three gas jet injection nozzles, wherein each of the at least three gas jet injection nozzles have a length established at between approximately 0.1 and 4.0 inches, and wherein each of the at least three gas jet injection nozzles have an inner aperture diameter established at between approximately 0.030 and 0.04 inches;orienting each of the at least three gas jet injection nozzles to interact with each other at a location above an operational surface of the substrate, to include spacing the at least three gas jet injection nozzles substantially evenly apart within a same plane and orienting each of the at least three gas jet injection nozzles at an acute angle with respect to a proximal surface of the substrate of between approximately 50 and 60 degrees to the proximal surface of the substrate so that a longitudinal axis of the each gas jet injection nozzle extends to a location on the proximal surface of the substrate of between approximately 9 and 13 percent of a length of the proximal surface of the substrate to thereby provide for a growth rate of diamond film on the substrate of between approximately 7 and 9 microns per hour;orienting each directed gas stream to interact with at least one other directed gas stream and with the microwave plasma discharge when generated within the microwave plasma chamber to thereby enhance growth rate of a film on an operational surface of a substrate while maintaining substantial uniformity of the film;interfacing each of the at least three gas jet injection nozzles with a respective one of a plurality of reactant gas injection ports in a proximal end portion of the microwave plasma chamber; andimparting substantial kinetic energy to the directed gas stream sufficient to disturb a boundary layer above the substrate, intensifying and flattening a hemispherical shape of the microwave plasma discharge, to thereby increase an impingement rate of reactant material on the operational surface of the substrate, the increased impingement rate resulting in a substantial increase in growth rate of deposited film material, the diamond film produced by the electrodeless microwave plasma reactor having a thickness of between approximately 100 μm and 5 mm at an optical quality characterized by an absorption coefficient less than 1.05 cm−1 at an electromagnetic wavelength between 7 to 14 μm. 13. A method as defined in claim 12, further comprising the steps of: establishing the velocity of gas exiting each gas jet injection nozzle at between approximately 10 and 300 meters per second;establishing an operational flow rate of the reactant gas entering the microwave plasma chamber at between approximately 0.3 and 1 standard liters per minute;establishing a composition of the reactant gas at between approximately 0.5 and 4 percent carbon precursor;establishing an operational temperature of the substrate at between approximately 780 and 1200 degrees Centigrade; andestablishing an operational pressure within the microwave plasma chamber at between approximately 50 and 200 Torr. 14. A method for forming large diameter high quality diamond film while maintaining substantial uniformity of the diamond film, the method comprising the steps of: providing a microwave plasma reactor with a substrate positioned within a microwave plasma chamber;establishing an operational flow rate of reactant gas entering the microwave plasma chamber;establishing an operational temperature of the substrate at between approximately 780 and 1200 degrees Centigrade;establishing an operational pressure within the microwave plasma chamber at between approximately 50 and 200 Torr;generating a microwave plasma discharge within the microwave plasma chamber immediately proximate to the substrate;configuring a plurality of directed gas jet injection nozzles each to create a directed gas stream of reactant gas substantially toward the substrate within the microwave plasma chamber of the microwave plasma reactor, the plurality of directed gas jet nozzles comprising at least three gas jet nozzles, the at least three gas jet nozzles being positioned at an angle of between approximately 50 and 60 degrees to a proximal surface of the substrate so that a longitudinal axis of the each gas jet injection nozzle extends to a location on the proximal surface of the substrate positioned between approximately 9 and 13 percent of a length of the proximal surface of the substrate, each directed gas stream oriented so as to interact with the microwave plasma discharge to provide an enhance growth rate of diamond film on the substrate;directing the gas stream of reactant gas for each of the directed gas jet injection nozzles toward the substrate to interact with the microwave plasma discharge; andforming a diamond film having substantial uniformity on an operational surface of the substrate responsive to the combination of steps of establishing the respective operational substrate temperature of between approximately 780 and 1200° C., establishing the respective operational microwave plasma chamber pressure of between approximately 50-200 Torr, generating the microwave plasma discharge proximate the substrate, and directing the gas stream of reactant gas cause interaction of the directed gas streams with the microwave plasma discharge proximate the substrate while maintaining the respective operational substrate temperature and operational microwave plasma chamber pressure. 15. A method as defined in claim 14, wherein step of forming a diamond film having substantial uniformity on an operational surface of the substrate comprises forming a diamond film having a diameter of at least 2 inches on the operational surface of the substrate while maintaining substantial uniformity. 16. A method as defined in claim 14, wherein each of the plurality of directed gas streams is oriented to interact with at least one other directed gas stream of the plurality of directed gas streams and with the microwave plasma discharge when generated within the microwave plasma chamber to thereby enhance growth rate of the diamond film on an operational surface of the substrate while maintaining substantial uniformity of the diamond film. 17. A method as defined in claim 16, wherein the plurality of directed gas jet injection nozzles includes at least three gas jet injection nozzles; andwherein the step of orienting each directed gas stream includes the steps of: configuring a plurality of reactant gas injection ports to each receive a separate one of the plurality of directed gas jet injection nozzles, each of the plurality of reactant gas injection ports extending through a proximal end portion of the microwave plasma chamber at a location substantially upstream of a location of the microwave plasma discharge when generated and above the operational surface of the substrate,interfacing each of the at least three gas jet injection nozzles with a corresponding at least three of the plurality of reactant gas injection ports spaced substantially evenly apart within a same plane, andorienting each of the at least three gas jet injection nozzles at a substantially same acute angle with respect to the operational surface of the substrate to improve uniformity and manage a shape of the microwave plasma discharge. 18. A method as defined in claim 17, wherein the step of configuring a plurality of reactant gas injection ports includes modifying a size of each of at least three existing gas injection ports;wherein the plurality of directed gas jet injection nozzles includes at least a fourth gas jet injection nozzles; andwherein the step of orienting each directed gas stream further includes the steps of: interfacing the at least a fourth gas injection nozzle with a corresponding one of the plurality of reactant gas injection ports positioned upstream of the microwave plasma discharge and substantially above a center of the operational surface of the substrate when the substrate is operably positioned within the microwave plasma chamber, andorienting the at least a fourth gas jet injection nozzle at an angle approximately normal to the operational surface of the substrate. 19. A method as defined in claim 16, further comprising the steps of: establishing the velocity of gas exiting each gas jet injection nozzle at between approximately 30 and 150 meters per second; andestablishing a composition of the reactant gas at between approximately 0.5 and 4 percent carbon precursor with respect to hydrogen. 20. A method as defined in claim 19, further comprising the steps of: establishing an operational flow rate of the reactant gas entering the microwave plasma chamber at between approximately 0.3 and 1 standard liters per minute. 21. A method as defined in claim 16, wherein the diamond film is a thermal management grade diamond film;wherein the growth rate of diamond film on the substrate is greater than approximately 7 microns per hour; andwherein the step of configuring the microwave plasma reactor includes configuring the reactor so that the diamond film produced by the reactor has a thickness of greater than approximately 100 microns and a thermal conductivity above about 1000 W/Kelvin-meter. 22. A method as defined in claim 16, wherein the diamond film is an optical grade diamond film;wherein the growth rate of diamond film on the substrate is greater than approximately 7 microns per hour; andwherein the step of configuring the microwave plasma reactor includes configuring the reactor so that the diamond film produced by the reactor has a thickness of greater than approximately 100 microns and an optical quality characterized by an absorption of less than 5% at a wavelength of between approximately 7.9 and 10.6 micrometers and an absorption of less than 10% at a wavelength of between approximately 10.6 and 12.0 micrometers. 23. A method as defined in claim 16, wherein the plurality of directed gas jet nozzles include at least three gas jet injection nozzles, wherein each of the at least three gas jet injection nozzles have a length established at between approximately 0.1 and 4.0 inches, and wherein each of the at least three gas jet injection nozzles have an inner aperture diameter established at between approximately 0.030 and 0.04 inches, the method further comprising the steps of: interfacing each of the at least three gas jet injection nozzles with a respective one of a plurality of reactant gas injection ports in a proximal end portion of the microwave plasma chamber; andorienting each of the at least three gas jet injection nozzles to interact with each other at a location above an operational surface of the substrate, to include spacing the at least three gas jet injection nozzles substantially evenly apart within a same plane and oriented at a substantially same acute angle with respect to a proximal surface of the substrate of between approximately 50 and 60 degrees to the proximal surface of the substrate to thereby provide for a growth rate of the diamond film on the substrate between approximately 5 microns per hour and approximately 10 microns per hour.