Cl_2-Etching and MBE-Regrowth for GaAs/AlO_x Photonic Crystals

摘要

We propose a new method for fabricating high index contrast gratings made of gallium arsenide (GaAs) and aluminum oxide (A1O_x) buried in GaAs based waveguide structures. A central part of this method is a UHV-compatible thermal chlorine etch and MBE-regrowth on etched GaAs and Al_xGa_(1-x)As. We describe results on surface roughness evolution during the etch obtained by in-situ elastic light scattering. These measurements allow us to determine the process parameters that lead to a smooth etched surface on which we demonstrate successful regrowth.