Abstract A triode sputtering apparatus to deposit material on the surface of an article. The apparatus comprises an enclosure means for evacuating the enclosure, a means for establishing an ion plasma in the enclosure. An ion target, including two members with surfaces of the material to be sputtered, is located in the enclosure with the surfaces facing the ion plasma. The target members are electrically biased so that ions from the plasma will impinge on their surfaces and sputter material therefrom. An article having a surface to be coated is mounted in the enclosure so that the surface faces the ion plasma and the sputtering surfaces of the target which are at an acute angle to the surface of the article. An electron funnel is used to funnel electrons being supplied to the plasma between the article and the target and an elongated anode is used to attract electrons from the plasma. The apparatus may be used to coat 11 by 11 inch glass plates with a metallic layer having substantially uniform optical density.
In a triode sputtering coating apparatus for coating a surface of a substrate, said apparatus including: a. a container; b. means for establishing an electron discharge to provide an ion plasma in said container, said means including cathode means in spaced relation with an anode; the improvement which comprises: c. first and second target electrodes, said target electrodes being spaced from each other and inclined relative to each other at an obtuse angle, said second target electrode being positioned closer to said anode than said first target electrode; d. means for supporting a substrate opposite said target electrodes and subtending said obtuse angle whereby material can be sputtered from the targets onto a substrate mounted on said support means; and e. electric bias means for establishing a first predetermined negative potential on said first target surface and a second predetermined negative potential on said second target surface, said second negative potential being greater than said first negative potential.