Davaji - Piezoelectric w-AlN Lateral Bimorph

We presented a fabrication process for AlN in-plane bimorph devices. We observed the interdependencies between the plasma etching characteristics and the crystal quality of the deposited films. At this point, the mechanism that relates crystal quality to the etch process is not clear to us and is actively being studied by the investigators. We identified a pathway for independently controlling the film quality by altering surface roughness of the underlying oxide layer. This work indicates that the underlying substrate and its structure directly impacts AlN crystal formation, the uniformity and growth properties on compound substrates, and subsequently the etch mechanism and uniformity across the wafer.