The samples were fabricated on a silicon wafer with thermally grown2 mm silica and 100 nm low-pressure chemical vapour deposited high-stressstoichometric Si3N4 thin films on top. The beam was created using electron-beamlithography followed by a timed C4F8–SF6 reactive ion etch. In a second lithographystep, the polymer mask for the microdisk resonator was defined in such a way thatthe disk partially overlapped the beam. The microdisk resonator was created using awet etch in a buffered hydrofluoric bath. Owing to the isotropic nature of this etch,material below the polymer mask was partially etched, resulting in an angledsidewall of the microdisk. Using this effect and ensuring the correct alignment of thedisk mask with respect to the beam, the release of the beam was achieved with thestructure being positioned above the wedge of the microdisk resonator. Release of thecombined system was accomplished by anisotropic silicon etching in a potassiumhydroxide bath.
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