Fig. 3: Fabrication of centimeter-scale nanoresonators.
From: Centimeter-scale nanomechanical resonators with low dissipation
a–f Schematic of the fabrication process composed of Si3N4 patterning via dry etching (a), mask removal (b), cryogenic DRIE silicon etching with photoresist mask (c), mask removal (d), Si3N4 undercut (e), and Si3N4 suspended over a large gap (f). g SF6 release step when the Si3N4 structure is suspended after being patterned, leading to collapse due to the short distance with the supporting silicon wafer. h SF6 release step with micro-scaffolding when the Si3N4 structure is suspended after a DRIE of the supporting silicon wafer, resulting in a large gap and high-yield release. i False-colored scanning electron microscope pictures of the optimized 3 cm nanoresonators at the clamping area (top), at the boundary of the first unit cell (bottom-left), and at the center (bottom-right). The blue area indicates the area where Si3N4 is suspended, consisting of the string and the overhang. j Photograph of a chip containing fourteen centimeter-scale nanoresonators, each 3 cm long.
