  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.
