Method for the Vacuum Deposition of Optical Coatings on Polymethyl Methacrylate

Abstract

Physical vapor deposition (PVD) of optical coatings on polymethyl methacrylate (PMMA) is known to be problematic because of poor coating adhesion. In this study, we were able to show that short‐wavelength radiation emitted by the coating procedure causes degradation of the PMMA interface and consequently inhibits the adhesion of deposited layers. Allowing for this fact, we developed an anti‐reflection coating that provides good adhesion on PMMA solely by the absorption of this damaging radiation in the first protective layer.

Antireflection Coating on PMMA Substrates by Atomic Layer Deposition

“…Different deposition methods based on wet chemistry, physical vapor deposition (PVD) and chemical vapor deposition (CVD) techniques, such as sol-gel method [4], ion and plasma assisted PVD processes [5] and plasma enhanced chemical vapor deposition (PECVD) [6] have been applied on PMMA and other plastic substrates with a motivation of enhancing their optical functionalities. Previous research suggests a special direct current (DC) glow discharge plasma pre-treatment [7,8], or a vacuum ultraviolet (VUV) protection layer by boat evaporation [9] prior to the plasma ion assisted depositions to improve the adhesion of thin films on PMMA. Several other approaches involving moth eye structures by full wafer and roll-to-roll nano-imprint lithography (NIL) [10], layer-by-layer assembly of hollow silica nanoparticles [11] and porous quarter wave antireflection coatings (ARC) with colloidal nanospheres [12] have also been demonstrated for ARC on plastics.…”