Microfabrication of large area high-stress silicon nitride membranes for optomechanical devices

TL;DR

This paper presents a new fabrication process for large-area, high-stress silicon nitride membranes suitable for optomechanical devices, maintaining optical and mechanical quality for advanced MEMS applications.

Contribution

A general DRIE-based fabrication method for high-quality, large-area SiN$_x$ membranes tailored for optomechanical resonators is introduced, enabling integration with complex MEMS structures.

Findings

Membranes exhibit high mechanical quality factors.

Optical quality of membranes is preserved after fabrication.

Membranes are suitable for use in interferometric and cavity-based optomechanical systems.

Abstract

In view of the integration of membrane resonators with more complex MEMS structures, we developed a general fabrication procedure for circular shape SiN$_x$ membranes using Deep Reactive Ion Etching (DRIE). Large area and high-stress SiN$_x$ membranes were fabricated and used as optomechanical resonators in a Michelson interferometer and in a Fabry-P\'erot cavity. The measurements show that the fabrication process preserves both the optical quality and the mechanical quality factor of the membrane.