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Intrinsically Tunable Laminated Ferroelectric Sc0.28Al0.72N Extensional Resonator based on Local Polarization Switching Shaurya Dabas Authors: Shaurya Dabas, Dicheng Mo, Sushant Rassay, Roozbeh Tabrizian Faculty Mentor: Roozbeh Tabrizian, PhD College: College of Engineering Department: Electrical and Computer Engineering |
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AbstractThis poster reports, for the first time, on an intrinsically tunable Scandium Aluminum Nitride (Sc0.28Al0.72N) width extensional resonator based on the use of local polarization switching concept. A laminated resonator is created from alternative stacking of two ferroelectric Sc0.28Al0.72N films with metal layers. This architecture enables independent control over local polarization across transducer thickness and width. Local polarization reversal of the top Sc0.28Al0.72N film, through application of switching pulses between top and middle electrode, results in a reduced net polarization and electromechanical coupling. This translates to the stiffening of the transducer and an increase in acoustic velocity and resonance frequency. The local polarization switching concept is demonstrated using a 97 MHz laminated ferroelectric Sc0.28Al0.72N resonator operating in 3rd width-extensional mode, with a Q of ~700 and kt2 of 2.26%. A frequency tuning of 0.65% is achieved through application of fifteen ~78V monopolar pulses at 20kHz. The achieved tuning range exceeds the overall 0.53% temperature-induced frequency drift in the resonator over -40°C to 80°C. This highlights the effectiveness of the local polarization switching approach for frequency stabilization of Sc0.28Al0.72N bulk acoustic resonators for frequency reference and spectral processing applications.
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Poster
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