Abstract
This thesis is devoted to the discussion of aluminum nitride (ALN) which thin film deposition for BAW devices has the obvious C-axis direction is deposited by RF-Sputtering. The C-axis orientation of the aluminum nitride film will affect the high frequency bulk acoustic wave device performance. By the results of experiments, we find that if we want a perfect C-axis direction of thin aluminum nitride film, we must control four process parameters, mainly: the chamber pressure is 4m (torr), the substrate temperature is 400°C, the sputtering power is 350W and the percent of nitrogen in the process gas is 60%. We analyzed the binding energy, the chemical content of thin film by the X-RD and S parameter of the device with Network Analyzer. The design of the device input/output pads for the high frequency bulk acoustic wave device plays an important role, we have to consider the geometry of the wave guide line which effects the device. We have successfully deposited C-axis oriented ALN thin film and the preliminary measurement on the BAW device shows that the acoustic wave velocity for the ALN film obtained from the S parameter measurement is about 7000 m/sec, assuming to the factors contributed to the resonance frequency deviation. This result is about 70% of the ideal value.