Nano SAW Devices For Sensing Applications
One goal of this project was to design and fabricate SAW sensors on lithium niobate chips with the best resolution photolithography in CMi to test our general ability to fabricate such devices at EPFL. The other goal of this project was to study as many different devices as possible during the first fabrication runs to find the best layouts for future device designs. In this project, the theory of SAW devices is discussed, including the wave production and propagation, the piezoelectric materials, the different components of SAW devices and modelling them. A mask was designed with several different interdigital transducers, two different reflectors and a variety of adaptions to the length, aperture and angle of propagation of the SAW devices. With the help of the CMi staff, the process flow was optimized for fabricating the devices. Three exposure tests were made to optimize the photolithography portion of the fabrication. In the end, two chips were fabricated with several good quality IDTs and a few good reflector arrays.