Reactive Ion Beam Etching (RIBE) is a technique well suited to etching slanted features. The technique allows localised removal of material using a broad ion beam. The material is removed at the wafer surface following collisions between accelerated ions and reactive species formed in the ion source.
Control and repeatability in defining slanted features is contingent on advanced Ion beam source configuration and experienced selection of processing conditions.
In this paper, we describe how our solution delivers controlled processing of slanted gratings used as a light coupler for Augmented Reality waveguide combiners. We demonstrate control of the slant angle, the groove depth and the filling ratio for large wafer sizes...