For Fbar Technology Ain Film

Recently, the enormous growth in personal communications systems(PCS) has made analogue frequency control a key issue as the operation frequency increases to the low/medium GHz range. At the frequency of the interests and the minimization of the devices, the filter such as ceramic filters or surface acoustic wave(SAW) filters can not be suitable. Thin film bulk acoustic resonator (FBAR) is a breakthrough technology for RF filter. It can replace conventional SAW filter because it provides several prominent advantages such as small size, high Q, high power handling capability, high operating frequency, good temperature stability, and the possibility of being integrated into RFIC (Radio Frequency Integrated Circuits).Deposition of high-quality AlN thin film is a key to success in FBAR manufacture. The AlN thin film has grown using both RF and pulsed-DC reactive sputter deposition on some substrate materials. It is necessary to have very good process control of such process. The thesis explains how different parameters affect the reactive sputtering process and the sputtering velocity and the c-axis orientation of AlN Film by theory and experiment. The depth of the AlN film has improved to 2.3um successfully by the RF reactive sputter. The result show that specially designated N₂ partial pressure(20%-25%), reduction of N₂ flow rate ratio , the increase of sputtering power, appropriately high substrate temperature, short target-substrate distance can obtain much higher sputtering velocity and the c-axis oriented. Finally large-dimension piezoelectric resonator has been manufactured.