Study On Deposition And Analysis Of LiNbO₃ And H-BN Films For Multilayered SAW

Surface acoustic wave filter is widely used in modern wireless mobile-communication system because of its advantages,such as high central frequency and its lower insert loss.The central operating frequency of SAWF is defined as f = V L,among which V means the SAW speed of the used material,and L is the period of its interdigital transducer(IDT)..Diamond comes to light because of its very high acoustic propagating speed,but diamond films is not the epiezoelectric films,so it is possible to fabricate high frequency SAWF device using piezoelectric films on diamond substrates based on the predent technology.Lithium niobate film were deposited on diamond by RF magnetron sputtering, and we get highly c-axis oriented LN thin films.In this thesis,we deposited LN and BN films on diamond and silicon substrates by radio frequency(RF) magnetron sputtering.The thin films are structurally analyzed using techniques such as bragg X-ray diffraction.The main work can be described as following:We use LiNbO3 powder target to deposite LiNbO3 on diamond by RF magnetron sputtering,and LN films were deposited on diamond substrate and the effects of the main deposition paremetere such as sputtering temperature and target power on thin fims were discussed. Our results show that it is possible to deposite LN on diamond substrate under the high temperature about 600oC and higher target power 80W.Secondly,based on the results,we try to deposite LN films on silicon with ceramic target.,and under the optimized condition highly property LN films are fabricated.Finally,we explored the fabrication technology of Boron Nitride thin fims on diamond and silicon.Our results show that it is possible that the piezoelectric films can be fabricated by RF magnetron sputtering,but there is a long way to go to make clear how the films can be deposited successfully on diamond and silicon.In a word,with a series of research,the paper discussed the effect of the deposition parameters,like temperature and target power on microstructure and electricity performance of films.And these results are suitable for the fabrication of surface acoustic wave fiter.