Low-loss GeO2thin films deposited by ion-assisted alternating current reactive sputtering for waveguide applications

We report low optical loss germanium oxide (GeO2) thin films which have been deposited by low pressure ion-assisted alternating current dual magnetron sputtering of germanium targets in an oxygen plasma environment. The germanium oxide films ranging from 0.7- to 1.0-µm-thick were fabricated at low temperature and high deposition rates of 6–38 nm/min on silicon and thermally oxidized silicon substrates. The refractive index of the films was …