Abstract
Layered structure Pt/AlN/sapphire is a promising candidate for SAW high temperature sensor due to its stable piezoelectric properties up to 1000 °C. Low electromechanical coupling k2 of the SAW in AlN/sapphire which does not exceed 0.3% that substantially limit its application. Novel type of the “hybrid” piezoelectric transducer implementing the mutual transformation of BAW to SAW was published in [1,2]. Hybrid transducer consist of the piezoelectric pillars spaced on the distance of λ/2. Each pillar works as a BAW transducer but due to the λ/2 spacing BAW in pillars transforms into SAW on the substrate. This transducer possesses high electromechanical coupling k2 respect to AlN/sapphire SAW device. In present work the conventional interdigital transducer (IDT) was replaced by the hybrid transducer in a reflective delay line type high temperature sensor. Scandium doped piezoelectric AlN film (AlScN), 15% of Sc have been chosen as a transducer material that allowed to increase k2 up to 4%.
Original language | English |
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Publication status | Published - Sept 2021 |
Event | SAW Symposium 2021 - Dresden, Germany Duration: 14 Oct 2021 → 15 Oct 2021 http://www.saw-symposium.com/ |
Conference
Conference | SAW Symposium 2021 |
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Country/Territory | Germany |
City | Dresden |
Period | 14/10/21 → 15/10/21 |
Internet address |