Impact of Bosch and Reactive Ion Etching (RIE) Processes on Lithium Niobate (LiNbO3)

This project is carried out in the context of the research conducted by Florian Hartmann at the Advanced NEMS Laboratory, whose work focuses on the fabrication of LiNbO3- based acoustic resonators. In his process flow, silicon is etched using the SOI_accurate recipe while a thin LiNbO3 film sits underneath. To ensure complete consumption of the silicon layer, a deliberate over-etch is applied, meaning the plasma continues to run beyond the point where the Si is fully removed. During this over-etch phase, the LiNbO3 film is directly exposed to the fluorine-based plasma. The present project therefore aims to characterize the etch rate of LiNbO3 under these exact conditions, in order to quantify how much material is unintentionally removed during the over-etch and assess whether this affects the performance of the final resonator device.