Self-Sealing Complex Oxide Resonators

[Image: see text] Although 2D materials hold great potential for next-generation pressure sensors, recent studies revealed that gases permeate along the membrane-surface interface, necessitating additional sealing procedures. In this work, we demonstrate the use of free-standing complex oxides as self-sealing membranes that allow the reference cavity beneath to be sealed by a simple anneal. To test the hermeticity, we study the gas permeation time constants in nanomechanical resonators made from SrRuO(3) and SrTiO(3) membranes suspended over SiO(2)/Si cavities which show an improvement up to 4 orders of magnitude in the permeation time constant after annealing the devices. Similar devices fabricated on Si(3)N(4)/Si do not show such improvements, suggesting that the adhesion increase over SiO(2) is mediated by oxygen bonds that are formed at the SiO(2)/complex oxide interface during the self-sealing anneal. Picosecond ultrasonics measurements confirm the improvement in the adhesion by 70% after annealing.