Title :
The SAW properties of sputtered SiO2 on X-112°Y LiTaO3
Author :
Hickernell, Fred S.
Author_Institution :
Motorola Inc., Phoenix, AZ, USA
Abstract :
The surface acoustic wave (SAW) propagation properties on the X-cut plate, 112°Y rotated, lithium tantalate (LiTaO3) substrate with and without sputtered SiO2 film layers have been investigated using interdigital transducer electrode structures. Thicknesses of SiO2 of 500 nm and 1000 nm were sputter deposited on the X-112°Y LiTaO3 substrates. A series array of aluminum electrode patterns deposited on the film facilitated the excitation of a wide frequency band of harmonic waves up to 2.0 GHz, and permitted delineation of SAW velocity and propagation loss characteristics for several values of film-thickness to acoustic-wavelength (t/λ) ratio. A resonator pattern at the substrate/film interface, permitted the capacitance ratio (Cm/Co), related to coupling factor, and the temperature coefficient of frequency (TCF) to be measured. A high velocity pseudo-SAW (HVPSAW) mode was observed with a velocity near 6300 m/s
Keywords :
acoustic wave propagation; interdigital transducers; lithium compounds; silicon compounds; sputtered coatings; substrates; surface acoustic wave devices; 1000 nm; 112°Y rotated; 2 GHz; 500 nm; 6300 m/s; Al electrode patterns; LiTaO3 substrate; SAW velocity; SiO2-LiTaO3; X-112°Y LiTaO3; X-cut plate; acoustic-wavelength; delineation; harmonic waves; interdigital transducer electrode; propagation loss characteristics; pseudo-SAW mode; resonator pattern; series array; sputtered SiO2; temperature coefficient of frequency; up to 2.0 GHz; velocity near 6300 m/s; Acoustic propagation; Acoustic transducers; Acoustic waves; Aluminum; Electrodes; Frequency; Lithium compounds; Propagation losses; Substrates; Surface acoustic waves;
Conference_Titel :
Frequency Control Symposium and Exhibition, 2000. Proceedings of the 2000 IEEE/EIA International
Conference_Location :
Kansas City, MO
Print_ISBN :
0-7803-5838-4
DOI :
10.1109/FREQ.2000.887357
