Patent Number: 8,817,367

Title: Plasma ion assisted deposition of Mo/Si multilayer EUV coatings

Abstract: The disclosure is directed to multilayer Mo/Si coatings for reflective mirrors used in extreme ultraviolet lithographic systems and to a method of making such mirrors using plasma ion assisted deposition (PIAD) techniques. The coating are deposited on a substrate suitable for EUV lithography, and are Mo/Si coating consisting of 40-100 Mo/Si periods, each period consisting on a Mo layer followed by a Si layer. Each of the individual Mo and Si layers is deposited to a specified or target thickness in the range of 2 nm to 5 nm, and the thicknesses are controlled to .+-.0.1 nm. A plasma from a plasma source is used to densify and smooth the substrate prior to deposition of the coating, and each layer of the coating is plasma densified and smoothed.

Inventors: Schreiber; Horst (Corning, NY), Wang; Jue (Fairport, NY)

Assignee: Corning Incorporated

International Classification: G02B 5/08 (20060101)

Expiration Date: 8/26/12018