Freestanding HfO 2 grating fabricated by fast atom beam etching

Abstract

We report here the fabrication of freestanding HfO 2 grating by combining fast atom beam etching (FAB) of HfO 2 film with dry etching of silicon substrate. HfO 2 film is deposited onto silicon substrate by electron beam evaporator. The grating patterns are then defined by electron beam lithography and transferred to HfO 2 film by FAB etching. The silicon substrate beneath the HfO 2 grating region is removed to make the HfO 2 grating suspend in space. Period- and polarization-dependent optical responses of fabricated HfO 2 gratings are experimentally characterized in the reflectance measurements. The simple process is feasible for fabricating freestanding HfO 2 grating that is a potential candidate for single layer dielectric reflector. © 2011 Wang et al.