COLD CATHODE AND METHODS FOR PRODUCING THE SAME

摘要

The present invention relates to the production of highly efficient films for field-effect electron emitters, wherein said films may be used in the production of flat displays in electronic microscopes, in microwave electronics, in light sources, etc. This invention more precisely relates to a cold cathode that comprises a substrate having a carbon film applied thereto. The carbon film has an irregular structure consisting of carbon micro-ridges and/or micro-threads which are perpendicular to the surface of the substrate, have a size ranging typically from 0.01 to 1 micron and a distribution density of between 0.1 and 10 mu m<-2>. This invention also relates to method for producing a cold electrode, wherein said method comprises generating a DC current discharge with a current density of between 0.15 and 0.5 A/cm<2> in a mixture comprising hydrogen and a carbon-containing additive, and further depositing the carbon phase on the substrate located at the anode. The deposition process is carried out in a mixture containing hydrogen and vapours of ethylic alcohol or methane, under an overall pressure of between 50 and 300 Torrs and at a substrate temperature of between 600 and 900 DEG C. The concentration of ethylic alcohol vapours ranges from 5 to 10 % while that of methane vapours ranges from 15 to 30 %. A method for producing a cold cathode comprises generating a microwave discharge at an absorbed power of between 100 and 1000 W. This discharge is generated in a mixture containing gaseous carbon oxide as well as methane in a 0.8-1.2 concentration and under a pressure of between 10 and 200 Torrs, and the carbon phase is further deposited on the substrate at a temperature on the substrate surface that ranges from 500 to 700 DEG C.