Graphene Metallization of High-Stress Silicon Nitride Resonators for Electrical Integration

TL;DR

This paper demonstrates that graphene coating on high-stress silicon nitride resonators allows for electrical integration with minimal quality factor degradation, enabling electrical readout and tuning while preserving mechanical performance.

Contribution

It introduces a novel graphene-based metallization method for silicon nitride resonators that maintains high quality factors and enables electrical functionalities.

Findings

Graphene coating reduces quality factor degradation to less than 30%.

Electrical readout and electro-static tuning are successfully demonstrated.

Hybrid graphene/nitride resonators combine electrical and mechanical advantages.

Abstract

High stress stoichiometric silicon nitride resonators, whose quality factors exceed one million, have shown promise for applications in sensing and signal processing. Yet, electrical integration of the insulating silicon nitride resonators has been challenging, as depositing even a thin layer of metal degrades the quality factor significantly. In this work, we show that graphene used as a conductive coating for Si3N4 membranes reduces the quality factor by less than 30 % on average, which is minimal when compared to the effect of conventional metallization layers such as chromium or aluminum. The electrical integration of Si3N4-Graphene (SiNG) heterostructure resonators is demonstrated with electrical readout and electro-static tuning of the frequency by up to 1 % per volt. These studies demonstrate the feasibility of hybrid graphene/nitride mechanical resonators in which the electrical properties of graphene are combined with the superior mechanical performance of silicon nitride.