Preparation of zinc oxide piezoelectric substrate for saw biosensor device

To develop the SAW device, piezoelectric substrate is one of important factor that improve performance device. The material used such as ITO (Indium Thin Oxide) or LiTaO3 (Lithium Tantalate) extremely affect the cost as well as the preparation methods. To overcome this problem, the material known as ZnO (Zinc Oxide) has been chosen as the thin film layer of piezoelectric in developing the biosensor. These ZnO thin film acts as piezoelectric layer that made contact with the sensing element before the signal convert from a biological signal to an electrical signal by the transducer. Solgel deposition technique was used and zinc acetate as precursor compound and 2-Methoxyethanol as solvent to form the sol-gel. This sol-gel then be spin coat on the SiO₂/Si substrate which will later to be anneal with oxygen to make the thin film more dense, thinner and has smoother surface quality and higher resistivity. The surface morphology, electrical and optical characterization of the thin films will be studied using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), Four Point Probe and UV-Visible Spectropohotometer.