A High-$Q$ 30nm-Thick MFM Resonator Using Ferroelectric Hafnium Zirconium Oxide

This paper reports a super-thin (30nm) integrated metal-ferroelectric-metal (MFM) nano-mechanical resonator using atomically engineered hafnium zirconium oxide (Hf
0.5
Zr
0.5
O
2
) transducer film. A 10nm-thick atomic layered Hf
0.5
Zr
0.5
O
2
film is sandwiched between top and bottom titanium nitride (TiN) electrodes 10nm-thick each) and is subjected to rapid thermal annealing treatment to engineer the as-deposited amorphous Hf
0.5
Zr
0.5
O
2
into a non-centrosymmetric orthorhombic crystal structure with large ferroelectric characteristic. The ferroelectric Hf
0.5
Zr
0.5
O
2
is used to implement doubly-clamped MFM resonator, with an aspect ratio exceeding 10,000:1, operating in out-of-plane flexural mode of vibration at ∼195 kHz, with a high-
$Q$
of ∼1,930 under moderate vacuum conditions (800mT). Furthermore, we demonstrate, the use of electrostrictive effect in switching and tuning of the electromechanical transduction in Hf
0.5
Zr
0.5
O
2
. With extreme miniaturization capability, robust mechanical properties at nanoscale, truly CMOS-compatible process, and intrinsic operation switchability, high-
$Q$
Hf
0.5
Zr
0.5
O
2
MFM nano-resonators are promising candidates for development of high-resolution resonant sensors and cm- and mm-wave RF filters.