A study on properties of SAW and the magnetic thin-film bond

We manufactured photo mask to make surface acoustic wave (SAW) filter that use special quality of these LiNbO/sub 3/ piezoelectric material (100). To make IDT electrode, we evaporated aluminum about 6000 /spl Aring/, and achieved lithography process by using e-beam evaporator. Filament evaporation method was selected to evaporate nickel magnetic thin film between Tx-IDT terminal and Rx-IDT terminal. Thickness of evaporated nickel was about 4000 /spl Aring/. Width of IDT electrode that is used here are 50 /spl mu/m and space between IDT electrodes is 50 /spl mu/m. Metal piece is 8 pair, the length of metal piece is 8 mm and the whole size is 52 mm/spl times/24 mm. The calculated SAW is 200 /spl mu/m. It is confirmed that manufactured LiNbO/sub 3/-IDT's center frequency is 18.1 MHz. The average velocity of SAW, that propagates LiNbO/sub 3/-IDT's Tx-IDT and Rx-IDT both terminal, measured v=3888/spl plusmn/2.565m/s. And SAW's average velocity, that propagates LiNbO/sub 3/-Ni-IDT's Tx-IDT and Rx-IDT both terminal, measured /sup v/=3827/spl plusmn/1.474m/s. While SAW passing magnetic thin films, its velocity decreased about 1.5% (61m/s).