ALN/ALSCN Acoustic Resonant Systems Based on Ultra-Thin Piezoelectric Films

The objective of this thesis is to introduce several advances into ultra-thin aluminum nitride/aluminum scandium nitride (AlN/AlScN) based acoustic resonant systems. Various microelectromechanical system (MEMS) acoustic resonators — surface acoustic wave (SAW), thin-film bulk acoustic resonator (FBAR), and Lamb wave resonators— were investigated by employing the ultra-thin piezoelectric films targeted for mobile filtering application toward the 5th generation (5G) millimeter wave bands. We approach our design considering the limitations of filter bandwidth and super high-frequency operation by marrying the advantages of highly-crystalline thin films with the piezoelectric boost from the addition of Sc to AlN alloys. This results in single-crystalline epitaxial AlScN films directly grown on Si substrate using molecular beam epitaxy (MBE). A critical performance metric of an acoustic resonator, Q×kt2 Figure of merit (FoM), is discussed with robust structures that overcome thin-film fabrication challenges. We propose resonator/filter design in future directions to fulfill the requirements for the compact radio frequency front-end (RFFE) filters towards the mm-wave frequency range.

Level thesis:degree_level

Doctoral

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2022

Author dc:creator

• Park, Mingyo

Advisor dc:contributor.advisor

• Ansari, Azadeh

Committee members dc:contributor.committeemember

• Ayazi, Farrokh
• Cressler, John D.
• Choi, Sukwon
• Brand, Oliver

• acoustic resonator/filter
• microelectromechanical system
• aluminum nitride
• aluminum scandium nitride
• surface acoustic resonator
• thin-film bulk acoustic resonator
• Lambwave resonator.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/1853/72657

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/72657