Fabrication And Research Of AlN/Diamond Multilayered Film Used In High Frequency SAW Device

With the research and development of high frequency communication, Surface Acoustic Wave (SAW) device is attracting interest increasingly. The development of high frequency system make market need more and more high frequency SAW. Due to traditional SAW material have low velocity of sound, usually less than 4000m/s, it can only used to low frequency device. Because diamond not only has the highest elastic constant of all substrates and the SAW velocity is more than 10,000m/s, but also has many specialty better than other material. Its high acoustic propagation makes it desirable substrate for SAW device which frequency more than 1,000MHz. So the SAW based on diamond receive an increasing attention and become one of most hot topic.In this paper, the theories of multilayer thin film SAW filter and IDT in have been expatiate. In experiment, Diamond as substrate are used to make A1N thin film for SAW filter. In this thesis piezo-electric films were deposited by D.C. magnetic sputtering method, which has high (002) oriented. The film have good quality in crystal, the surface is very smooth and plain. So the film we made are satisfied SAW need.We change the parameters such like negative bias voltage, temperature of substrate. And use different time and material of substrate. Probe into the conditions which can obtain high c tropism A1N thin films. Test microstructure of films used XRD and SEM. The AlN film are very suit for SAW.