Study On Production And Analysis On High Frenquency LiNbO₃/diamond Layered SAWF

With the research and development of high frequency(3G) communication products, Surface Acoustic Wave (SAW) device based on diamond is attracting interest because diamond has the highest elastic constant of all substrates and the SAW velocity is more than 10,000m/s. Although diamond is not piezoelectric, its high acoustic propagation makes it desirable substrate for SAW device when coupled with piezoelectric thin films such as LiNbO3 thin film. SAW characteristics in layered structure of interdigital-transducer (IDT) /LiNbO3/diamond have been calculated. These calculations predict the velocity value of the SAW to be more than10,000 m/sIn this thesis, lithium niobate film were deposited on different diamond substrates by radio frequency (RF) magnetron sputtering, and the structure and properties of the thin films were analyzed and characterized by X-ray diffraction (XRD)。The main deposition technology of LN thin films were detailedly discussed. And the main results can be described as following:Firstly, we use matlab software to simulate the frequency response of LN/Diamond multilayered structures SAWF and YZ-LiNbO3 monolayer SAWF by the coupling-of-mode (COM). And we can take the conclusion that when the design parameters are the same, the center frequency of LN/Diamond multilayered structures SAW filters is much higher than monolayer structures SAW filers,and its insert loss is lower then other.Secondly, LN thin films were deposited on diamond substrate and the effects of the main depositon parameters such as sputtering pressure, sputtering and proportion of oxygen and argon on thin films were discussed. The effects of sputtering temperature and sputtering power are disgussed in my partner Jia Lingchun'paper, you can offer it if it is necessary.Through the experiments we improved the deposition parameters.Lastly, on basis of multiplayered structures of"AIN/ c-BN/diamond"SAWF which are proposed firstly by our development group,we made a primary study of RF magnetron sputtering cBN on Si substrates.