Deposition method and apparatus using plasma discharge

• Main Author: WILLIAMSON; WELDON S
• Format: Patent
• Language: English
• Published: 11.02.1992
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

A Penning type plasma discharge is formed in an inert gas between a cathode and anode. A carbon source such as graphite is heated to vaporization temperature, and vaporized carbon atoms caused to flow therefrom into the plasma where they are ionized. The inert gas supply is then removed, and the plasma discharge is sustained by the carbon vapor. A substrate is mounted adjacent to, and at the same electrical potential as, the cathode. With the potential of the plasma being maintained at approximately 70 to 100V relative to the substrate, carbon ions are attracted to and deposited on the substrate to form a diamond layer. The initial inert gas plasma discharge may be used to sputter-clean the surface of the substrate prior to diamond deposition. A dopant or other additive material may be injected into the carbon plasma, thereby enabling the fabrication of microelectric or other devices in the diamond layer. A material other than carbon may be vaporized for deposition using the same process as for diamond deposition. In addition, the process may be modified to provide a plasma source of pure ions, which may be extracted and utilized for a purpose other than deposition of a material layer.