Abstract
The SAW characteristics of thin-film silicon nitride (Si/sub 3/N/sub 4/) on piezoelectric substrates of Y-Z and 64/spl deg/ Y-X lithium niobate, and 36/spl deg/ Y-X lithium tantalate have been measured in the frequency range from 30 MHz to above 1.0 GHz. Silicon nitride films 250, 500, and 1000 nm thick were deposited by plasma enhanced chemical vapor deposition (PECVD). The SAW velocity and propagation loss properties were measured using linear arrays of thin-film aluminum interdigital electrodes patterned on the upper film surface. The elastic constants of the films could be determined by fitting a theoretical velocity dispersion curve to the measured velocities for Rayleigh wave propagation. The SAW propagation loss values for the films on the different substrates were compared to the loss characteristics without the film layers. Temperature coefficient of frequency (TCF) measurements of the SAW velocity characteristics for the various film/substrate combinations were also made. The results of these measurements, comparative data on acoustic constants, and the performance enhancements for SAW devices which could be realized by the use of silicon nitride on piezoelectric substrates are discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.