Fabrication of high-aspect-ratio submicron-to-nanometer range microstructures in LiNbO₃ for the next generation of integrated optoelectronic devices by focused ion beams (FIB)

The fabrication of high-aspect-ratio submicron-to-nanometer range microstructures in LiNbO₃ using a state-of-the-art Schlumberger AMS 3000 focused ion-beam (FIB) system is presented. The submicron structures with about 330 nm width and 1600 nm depth are fabricated by employing XeF₂ gas-assisted gallium ion-beam etching with 50 pA of ion-beam current. A variety of optoelectronic devices such as microsensors, directional couplers, extremely compact electro-optic modulators, and wavelength filters could be built based on this type of high-aspect-ratio submicron structure in LiNbO₃, which may lead to the next generation of integrated optoelectronic devices that have higher levels of device integration and enhanced functionality.