Nanomachining and clamping point optimization of silicon carbon nitride resonators using low voltage electron beam lithography and cold development

Abstract

The authors report the nanomachining of sub-20-nm wide doubly clamped silicon carbon nitride resonators using low keV electron beam lithography with polymethyl methacrylate resist and cold development. Methodologies are developed for precisely controlling the resonator widths in the ultranarrow regime of 11–20 nm. Resonators with lengths of 1–20 μm and widths of 16–280 nm are characterized at room temperature in vacuum using piezoelectric actuation and optical interferometry. Clamping and surface losses are identified as the dominant energy loss mechanisms for a range of resonator widths. The resonator clamping points are optimized using an original electron beam lithography simulator. Various alternative clamping point designs are also modeled and fabricated in order to reduce the clamping losses.

Helium Ion Microscope-Assisted Nanomachining of Resonant Nanostrings

“…Such accuracy offers interesting possibilities for the tuning of mechanical properties of suspended structures. More specifically, local milling of nanostrings would enable the control of resonant mode shapes and clamping point design [ 18 , 34 , 35 ]. We thus report the first demonstration of HeIM-nanomachining for the post-fabrication tuning of nanomechanical resonators.…”

Diazonium Chemistry for the Bio-Functionalization of Glassy Nanostring Resonator Arrays

“…The use of a glassy material is amenable to release through anisotropic etching of the underlying silicon. Such a feature allows strings as narrow as 8 nm, as long as tens of microns, devoid of any undercut, and dried without the need of a critical point drying step [ 27 , 50 , 51 ]. In addition, SiCN offers tunability of its tensile stress through a controlled post-deposition anneal [ 52 ].…”