Method for producing smooth, dense optical films
AssigneeCorning Incorporated
InventorsGary Allen Hart, Robert LeRoy Maier, Jue Wang
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Abstract
The invention is directed to preparing optical elements having a thin, smooth, dense coating or film thereon, and a method for making such coating or film. The coated element has a surface roughness of <1.0 nm rms. The coating materials include hafnium oxide or a mixture of hafnium oxide and another oxide material, for example silicon dioxide. The method includes the use of a reverse mask to deposit the coating or film on a rotating substrate.
Claims16
A method of depositing a thin film of a selected material on the surface of a substrate using plasma ion assisted deposition, the method having the steps of:
- providing a vacuum chamber and within said vacuum chamber:
- providing a substrate on which a coating is to be deposited;
- providing at least one selected coating material source, or a mixture of coating materials source, and vaporizing said material(s) using an e-beam to provide a coating material vapor flux, said flux passing from said material source through a reversed mask to said substrate;
- providing plasma ions from a plasma source;
- rotating said substrate at a selected rotation frequency f;
- and
- depositing said coating material on said substrate as a coating film and bombarding said substrate and said film with said plasma ions before and during said material deposition process:
- wherein said flux is delivered to said substrate at an angle φ that is ≦20°.
A method for preparing a silica optical element having a coating of a selected material, said method comprising the steps of:
- providing a vacuum chamber and within said vacuum chamber:
- providing at least one selected coating material source, or a mixture of coating materials source, and vaporizing said material(s) using an e-beam to provide a coating material vapor flux, said flux passing from said material source through a reversed mask to said substrate;
- providing plasma ions from a plasma source;
- rotating said substrate at a selected rotation frequency f;
- depositing said coating material on said substrate and bombarding said substrate and said deposited materials with said plasma ions before and during said material deposition process;
- wherein:
- said rotational frequency f is in the range of 12 to 15 rpm, and said flux is delivered to said substrate at an angle φ that is ≦20°;
- and
- the surface of said substrate is bombarded with said plasma ions for a time in the range of 1-4 minutes prior to the deposition of the coating martial(s).
Dependencies are inferred from the claim text.