Reactive physical vapor deposition of Al mirrors protected with LiF overcoat, devices and processes

Abstract

The present disclosure relates to a process to protect deposited aluminum coatings with an overcoat of LiF dielectric layer produced with a reactive Physical Vapor Deposition (rPVD) process. This process includes exposing the freshly deposited Al film to a fluorine containing gas (XeF2) for immediate surface passivation. Next is the application of a Physical Vapor Deposited (PVD) LiF layer that is passivated with XeF2. This process produces LiF-protected Al coatings that are more durable than Al+LiF coatings produced by conventional PVD processes. The Al+LiF coatings produced with this rPVD process are observed to be broadband, more durable, and less hygroscopic than coating produced with standard PVD process. In particular, the innovation has utility in realizing an intrinsic high reflectance of aluminum in the critical far-ultra-violet (90-130 nm) spectral range, while also preserving the intrinsic broadband nature of the aluminum reflectance in the near-infrared and up to at least 2500 nm.

Dependencies are inferred from the claim text.