Off-axis magnetron sputter deposition of mirrors

Claim 1

An off-axis magnetron sputtering device for use in the construction of mirrors by sputtering a combination of alternating layers of material on a substrate surface a substrate, comprising: an air tight sputtering chamber capable of maintaining gas at a pressure required to establish a discharge having a substantially cylindrical outer wall and a first and a second cover perpendicular to a central axis of said cylindrical outer wall; a first cathode assembly disposed within said chamber in close proximity to said first cover, said first cathode assembly having a first target material on a first target surface of said first cathode assembly, said first target surface opposite said first cover, and perpendicular to said central axis; a second cathode assembly disposed within said chamber in close proximity to said second cover of said chamber having a second target material on a second target surface of said second cathode assembly, said second target surface being opposite said second cover and parallel to said first target surface; a sputter shield disposed between said first cathode assembly and said second cathode assembly, said sputter shield having said first target material on a surface facing said first cathode assembly and said second target material on a surface facing said second cathode assembly; a first magnet assembly situated behind said first cathode assembly and opposite said first target surface, said magnet assembly having lines of magnetic force that leave said first target surface and return to said first target surface; a second magnet assembly situated behind said second cathode assembly and opposite said target surface, said second magnet assembly having lines of magnetic force that leave said second target surface and return to said second target surface; a switchable radio frequency source having one contact connected to said chamber and a second contact switchably connected to either said first cathode assembly or said second cathode assembly; and substrate handling means for holding a plurality of substrates in an orientation such that the substrate surface to be coated is parallel with said central axis and such that a radial vector normal to said substrate surface perpendicularly intersects said central axis, said substrate handling means for causing the substrates to be rotated about said cathode assemblies, said substrate handling means also for positioning said substrates in one of a plurality of positions, a first position being such that a radial vector normal to said substrate surface perpendicularly intersects said central axis between said first cathode assembly and said sputtering shield, and a second position being such that a radial vector normal to said substrate surface perpendicularly intersects said central axis between said second cathode assembly and said sputtering shield.

Claim 24

A method of coating a substrate with a plurality of thin films, comprising the steps of: a. positioning a substrate adjacent to a first cathode such that said substrate is perpendicular to a first target surface of said first cathode, said first cathode and said substrate both being located within a gas filled chamber; b. applying an electrical potential between said first cathode and said gas filled chamber creating a gas discharge within said gas filled chamber and thereby causing sputtering of material from said first target surface onto said substrate, and rotating said substrate about an axis which is perpendicular to said first target surface and concurrently rotating said substrate about an axis which is normal to the surface of said substrate; c. repositioning said substrate adjacent to a second cathode such that said substrate is perpendicular to a second target surface of said second cathode, said second cathode and said substrate both being located within a gas filled chamber; d. applying an electrical potential between said second cathode and said gas filled chamber creating a gas discharge within said gas filled chamber and thereby causing sputtering of material from said second target surface onto said substrate, and concurrently rotating said substrate about an axis which is perpendicular to said second target surface and while also rotating said substrate about an axis which is normal to a surface of said substrate.

Claim 25

A method of coating a substrate with a plurality of thin films, comprising the steps of: a. positioning a substrate adjacent to a first cathode such that said substrate is perpendicular to a first target surface of said first cathode, said first cathode and said substrate both being located within a gas filled chamber; b. applying an electrical potential between said first cathode and said gas filled chamber creating a gas discharge within said gas filled chamber and thereby causing sputtering of material from said first target surface onto said substrate, and rotating said substrate about an axis which is perpendicular to said first target surface and concurrently rotating said substrate about an axis which is normal to the surface of said substrate; c. repositioning said substrate adjacent to a second cathode such that said substrate is perpendicular to a second target surface of said second cathode, said second cathode and said substrate both being located within a gas filled chamber; d. applying an electrical potential between said second cathode and said gas filled chamber creating a gas discharge within said gas filled chamber and thereby causing sputtering of material from said second target surface onto said substrate, and concurrently rotating said substrate about an axis which is perpendicular to said second target surface and while also rotating said substrate about an axis which is normal to a surface of said substrate.