Producing electric arc plasma in a curvilinear plasmaguide and substrate coating

An apparatus for producing an electric arc separated plasma flux comprising:

• a cold cathode made of evaporable material,
• an anode,
• a curvilinear plasmaguide shaped as a toroid portion,
• an electric magnetic coil encircling the plasmaguide,
• power sources for energising a plasmaguide body, arc discharge and electromagnetic coil,
• a toroidal plasmaguide made with a turn angle
• α=ArcCos(2r2−R2)/R2,
• where r and R are, respectively, a small and large toroid radii,
• the cathode being disposed within the plasmaguide and a working surface of said cathode is parallel to a cross-section of the plasmaguide in a place of said cathode positioning biased from a plasmaguide longitudinal axis and toward a wall of said plasmaguide with a lesser radius so that a centre of said working surface of said cathode is disposed on a radius Ro={square root over (r×R)} away from a toroid centre, where r and R are, respectively, a small and large toroid radii,
• the anode being disposed at an exit of the plasmaguide,
• a substrate surface being saturated with reaction gas, with a coating based on a cathode material being deposited,
• said curvilinear plasmaguide creating electric arc plasma within, and putting electric current through said plasma in a longitudinal direction for forming longitudinal magnetic and electric fields, continuous and uniform over a plasmaguide length of said plasmaguide between said cathode and said anode,
• the fields being directed toward or away from plasmaguide walls with ionic cleaning being preformed in an inert gas medium at a zero or a negative potential on said plasmaguide body of said plasmaguide and a voltage on the substrate positioned at an exit side of said plasmaguide,
• the substrate surface being saturated at potentials in a medium of reaction gas or a mixture of reaction gas and inert gas, with a positive, potential being applied when depositing said coating on the substrate surface of said plasmaguide;
• and
• wherein after the substrate surface has been saturated with reaction gas, ionic cleaning is carried out in inert gas medium.

A method of producing a coating on a substrate using an electric arc plasma ionic cleaning of substrate surface, comprising the steps of:

• saturating said surface with reaction gas,
• depositing a coating based on a cathode material,
• creating electric arc plasma within a curvilinear plasmaguide,
• putting electric current through said plasma in a longitudinal direction,
• forming longitudinal magnetic and electric fields, continuous and uniform over a plasmaguide length between a cathode and an anode,
• directing the fields toward or away from plasmaguide walls,
• performing ionic cleaning in an inert gas medium at a zero or a negative potential on a plasmaguide body and a voltage on the substrate positioned at a plasmaguide exit side,
• saturating the substrate surface at potentials in a medium of reaction gas or a mixture of reaction gas and inert gas, applying a positive potential while depositing coating on the plasmaguide wall surfaces, and
• wherein after the substrate surface has been saturated with reaction gas, ionic cleaning is carried out in inert gas medium.