Coaxial plasma arc vapor deposition apparatus and method

An apparatus for the deposition of an evaporated material from a cathode to a deposition surface beyond the radial extent of a porous anode using a plasma, said apparatus comprising:

• an enclosed chamber including a vacuum pump and a variable pressure gas source;
• said cathode formed from a first conductive material and placed on an axis having an axial extent;
• said porous anode formed from a second conductive material, said porous anode placed at a positive electrical potential with respect to said cathode and surrounding said cathode over said axial extent;
• a magnetic field generator providing a magnetic field parallel to said axis over said axial extent, said magnetic field being substantially unidirectional and substantially uniform in strength over said axial extent;
• an ion trap located between said cathode and said deposition surface, said ion trap having passages with a radial extent sufficient to trap particles having a trajectory outside a range of trajectories, and whereby ions which travel in a linear trajectory are trapped by said passages and ions which travel in a curved trajectory pass freely, said ion trap having a plurality of elongate vanes, each said vane extending continuously from a first point beyond the extent of said cathode electrode to a second point separated from said first point and also rotated circumferentially about said axis with respect to said first point, said plurality of vanes thereby providing a plurality of passages therebetween for the unimpeded passage of particles within said range of trajectories;
• where adjacent said elongate vanes of said ion trap carry a steering current travelling substantially parallel to said axis and of opposite polarity on adjacent said elongate vanes;
• a voltage applied between said cylindrical anode and said cathode creating and maintaining said plasma;
• whereby ions of said plasma travel from said cathode through said porous anode and to said deposition, and other ions which follow a radial trajectory outside said range are captured by said ion trap.

An apparatus for the deposition of an evaporated material from a cathode having a continuous outer surface onto the inner continuous surface of a cylindrical anode using a plasma, said apparatus comprising:

• an enclosed chamber including a vacuum pump and a variable pressure gas source;
• said cathode formed from a first conductive material and placed on an axis;
• said cylindrical anode formed from a second conductive material, said cylindrical anode placed at a positive electrical potential with respect to said cathode, said cathode positioned within said cylindrical anode over an axial extent of said axis;
• a macro-particle filter disposed between said cathode and said anode, said macro-particle filter having continuously formed vanes separated from other said vanes, the gap between said vanes forming passages having sufficient radial extent to trap plasma particles having a linear trajectory, and to allow the passage of particles having the trajectory of an arc with curvature in a single direction;
• a magnetic field generator providing a magnetic field parallel to said axis over said axial extent, said magnetic field being substantially unidirectional and substantially uniform over said axial extent where said continuously formed vanes of said macro-particle filter are arranged substantially parallel to said axis and carry a steering current of opposite polarity on adjacent said continuous radial vanes, said steering current generating a magnetic field sufficient to cause said macro-particle filter to guide the passage of ionized plasma particles through said continuous radial vanes, and to trap macroparticles.