April MIT Nano Seminar - Roozbeh Tabrizian

"Ferroelectric hafnia-on-semiconductor frequency control devices: Unleashing the power of nano-mechanics on chip"
Roozbeh Tabrizian
Associate Professor, NELMS Rising Star Endowed Professor
Department of Electrical and Computer Engineering
University of Florida

The incorporation of nanoscale piezoelectric transducers into advanced semiconductor nodes enables the direct implementation of high-frequency nanomechanical resonators onto CMOS chips. The discovery of metastable ferroelectric phase in hafnia heralds the long-awaited arrival of this integrated piezoelectric transducer. Hafnia films, already utilized in amorphous form as high-k dielectrics in standard semiconductor processes, can be further engineered to stabilize in the ferroelectric phase with significant piezoelectric coupling.

Hafnia piezoelectric transducers pave the way for the development of on-chip nanomechanical resonators with quality factors several orders of magnitude higher than solid-state counterparts. This exceptional performance, combined with seamless integration with electronic circuitry, enables the creation of on-chip clocks, local oscillators, and microwave filters, meeting the escalating frequency-control requirements in computing and communication applications.

This presentation will provide an overview of Tabrizian Lab’s work focusing on the development of nanoscale hafnia transducers and their application in creating semiconductor nanomechanical resonators, oscillators, and filters. Specifically, it will cover (1) temperature-insensitive hafnia resonators for on-chip clock generation; (2) massively integrated ferroelectric-gate fin filters for microwave spectral processing; and (3) self-amplified ferroelectric-on-SiGe resonators for electronics-free sustained oscillation.