Influence of ALN crystallinity on SAP waveguides

In this work, a comparison in the behavior of highly c-axis oriented and amorphous Aluminum Nitride (AlN) films as core layer in self-aligned pedestal (SAP) optical waveguides is presented, aiming to study the influence of AlN crystallinity in waveguiding. Optical losses characterizations were measured in these devices using the top-view technique at a visible wavelength (wavelength at 547 nm). AlN films were examined by X-ray diffraction (XRD) to determine their crystalline structure. Furthermore, Scanning Electron microscopy (SEM) technique was utilized to verify the geometrical definition of the optical waveguide.