Cubic phase MgxZn1−xO thin films for optical waveguides

Cubic phase MgxZn1−xO (x=0.83) (CPMZ) thin films are deposited on SiO2/Si(0 0 1) substrates by reactive electron beam evaporation for optical waveguide application. Morphology characterization of the films by atomic force microscopy shows that the surface is smooth with a root mean square roughness of 0.5 nm. X-ray diffraction shows that the films are highly (0 0 1) oriented and have good thermal stability up to high annealing temperature of 950 °C. Two optical waveguide modes are observed by prism-coupling measurements. The CPMZ stripe waveguides are well defined by standard photolithograph and a wet-etching method using H3PO4 etching solution. These unique characteristics may render the cubic phase MgxZn1−xO thin films potential application in waveguide devices.