Fabrication of low-loss channel waveguides in Al2O3 and Y2O3 layers by inductively coupled plasma reactive ion etching

Etching of amorphous Al2O3 and polycrystalline Y2O3 films has been investigated using an inductively coupled reactive ion etch system. The etch behaviour has been studied by applying various common process gases and combinations of these gases, including CF4/O2, BCl3, BCl3/HBr, Cl2, Cl2/Ar and Ar. The observed etch rates of Al2O3 films were much higher than Y2O3 for all process gases except for Ar, indicating a much stronger chemical etching …