Research On Deposition Piezoelectric Films On Diamond

Surface acoustic wave devices (SAWD) are one of the most necessary devices in communication system. In recent years, there has been an increasing interest in developing surface acoustic wave devices operating at high frequencies. In order to obtain high-frequency SAW devices, people always prefer two ways which are shorten the period of IDTs and search the new substrates with high velocity. The first way always need high precision ,and it`s cost is too expensive .So we prefer to search new substrates with high velocity.Diamond comes to light to its very high acoustic propagating speed ,but diamond films is not thepiezoelectric films, and so it is possible to fabricate high frequency SAW device using piezoelectric films on diamond substrates based on the predent technology. In this thesis, lithium niobate film were deposited on different substrates(such as silicon and diamond) by radio frequency (RF) magnetron sputtering, and the structure and properties of the thin films were analyzed and characterized by X-ray diffraction (XRD),scanning eletron microscopy (SEM) and so on in order to demermine their properties. 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 SAW filters 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 other structures,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 temperature, sputtering pressure,self-voltage, sputtering and proportion of oxygen and argon on thin films were discussed.In a word, based on a series of research, the deposition parameters on c-axis oreinted of LN were discussed,and under theoptimized condition highly property LN films based on SAWD have been fabricated.