Metal thickness impact on the performance of a resonator

This semester project investigates the influence of metal layer thickness on an acoustic resonator. The resonator is a 14x17 mm chip made up of four layers as shown in Figure 1, each with an essential role to play. Silicon (Si) forms the substrate, providing a stable mechanical base compatible with microelectronic technologies. Silicon dioxide (SiO2) acts as an insulating layer, limiting the loss of acoustic energy to the substrate while promoting good wave propagation. Y-cut lithium niobate (LiNBO3), a piezoelectric material, converts electrical signals into acoustic waves and vice versa, playing a central role in the resonator’s operation. Finally, aluminum (Al), used for the electrodes, generates the electric field required for wave excitation and detection. It is precisely this last layer of aluminum that we are going to obtain in different thicknesses thanks to the use of Cmi’s cleanroom equipment.