Device And Method For Applying A Carbon Layer

Abstract

The invention relates to a device (1) and method for applying a carbon layer, in particular a diamond layer, to a substrate (2, 2a) by means of chemical vapour deposition, comprising a deposition chamber (3) into which a process gas, in particular molecular hydrogen and/or a mixture of molecular hydrogen and a carbon-containing gas, such as methane can be supplied, wherein a gas inlet and gas activation element (7) is provided in the form of a hollow body with a flow channel (7b) for the process gas, a wall (7a) surrounding the flow channel (7b), and an outlet opening (16) feeding from the flow channel (7b) into the deposition chamber (3), and a heating device (8) is provided for heating the wall (7a) of the gas inlet and gas activation element (7).

1 - 14 . (canceled) 
     
     
         15 . A device for applying a carbon layer to a substrate by chemical vapour deposition, said device comprising a deposition chamber, into which a process gas is fed, wherein a gas inlet and gas activation element is provided in the form of a hollow body with a flow channel for the process gas, a wall surrounding the flow channel and an outlet opening feeding from the flow channel into the deposition chamber, and a heating device is provided for heating the wall of the gas inlet and gas activation element, wherein termination bodies are attached to ends of the gas inlet and gas activation element in order to close off the flow channel, wherein a further gas inlet element is provided for introducing a carbon-containing process gas into the deposition chamber, wherein the further gas inlet element is arranged so that the carbon-containing process gas introduced thereby flows over the gas inlet and gas activation element. 
     
     
         16 . The device according to  claim 15 , wherein the heating device is designed to heat the wall of the gas inlet and gas activation element to a temperature of more than 2000° C. 
     
     
         17 . The device according to  claim 15 , wherein the heating device comprises a power supply, connected to the wall of the gas inlet and gas activation element, for the resistance heating of the gas inlet and gas activation element. 
     
     
         18 . The device according to  claim 15 , wherein the gas inlet and gas activation element is arranged substantially horizontally in the deposition chamber. 
     
     
         19 . The device according to  claim 15 , wherein the at least one outlet opening is arranged on an underside of the gas inlet and gas activation element, the underside facing towards the substrate. 
     
     
         20 . The device according to  claim 15 , wherein the gas inlet and gas activation element comprises a number of outlet openings. 
     
     
         21 . The device according to  claim 15 , wherein the gas inlet and gas activation element is substantially circular or rectangular in cross-section. 
     
     
         22 . The device according to  claim 15 , wherein a plurality of gas inlet and gas activation elements are provided which can be heated by means of the heating device. 
     
     
         23 . The device according to  claim 15 , wherein the wall of the gas inlet and gas activation element consists of a metal. 
     
     
         24 . A method for applying a carbon layer to a substrate by chemical vapour deposition, wherein a process gas is introduced into a deposition chamber via a gas inlet and gas activation element, characterised in that a wall of the gas inlet and gas activation element is heated in such a way that the process gas flowing in the flow channel of the gas inlet and gas activation element is excited by impact excitation and thermal excitation, wherein termination bodies are attached to ends of the gas inlet and gas activation element in order to close off the flow channel, wherein a carbon-containing process gas is introduced into the deposition chamber via a further gas inlet element, wherein the carbon-containing process gas is thermally excited by flowing over the gas inlet and gas activation element. 
     
     
         25 . The method according to  claim 24 , characterised in that the wall of the gas inlet element is heated to a temperature of more than 2000° C. 
     
     
         26 . The device of  claim 15 , wherein said carbon layer is a diamond layer, and said process gas is molecular hydrogen or a mixture of molecular hydrogen and a carbon-containing gas. 
     
     
         27 . The device of  claim 15 , wherein the heating device is designed to heat the wall of the gas inlet and gas activation element to a temperature of more than 2200° C. 
     
     
         28 . The device of  claim 15 , wherein the heating device is designed to heat the wall of the gas inlet and gas activation element to a temperature of more than 2400° C. 
     
     
         29 . The device of  claim 15 , wherein the wall of the gas inlet and gas activation element consists tantalum, molybdenum, tungsten, rhenium, a ceramic material, graphite, or pyrolytic carbon or a composite material thereof. 
     
     
         30 . The device of  claim 15 , wherein the wall of the gas inlet and gas activation element comprises fibre-reinforced carbon. 
     
     
         31 . The device of  claim 15 , wherein said carbon containing gas is methane. 
     
     
         32 . The device of  claim 15 , wherein the wall of the gas inlet and gas activation element includes a coating formed from a pyrocarbon. 
     
     
         33 . The method of  claim 24 , wherein said carbon layer is a diamond layer, and said process gas is hydrogen, and said carbon-containing gas is methane. 
     
     
         34 . The method of  claim 24 , wherein the wall of the gas inlet element is heated to a temperature of more than 2200° C.