Presentation Information
[10p-E311-7]Spontaneous deflection of silica nanocantilevers under electron-beam exposure
Abbhiraj Singh1, Takahiro Namazu1,2, 〇Amit Banerjee1 (1.Kyoto Univ. of Advanced Science, 2.SRIS, Tohoku Univ.)
Keywords:
Electron-beam induced bending,Silica nanostructures,Scanning electron microscopy
Irradiation of electron-beam on silica nanostructures can introduce exotic phenomenon like superplasticity. In this work, we show that exposure to low-energy (1.5 – 10 keV) electron beams can also spontaneously induce large bending deformation in ultrathin silica nanocantilevers (2 µm×2 µm×40 nm) (Fig. 1(a)). Moreover, the bending direction (upward or downward) and rate (rapid or slow) can be controlled by simply changing the exposure condition (Fig. 1(b)-(c), Fig. 2(a)), such as the energy or the irradiation angle of the electron-beam. The observed phenomenon is akin to focused ion beam (FIB) induced bending but unlike FIB bending technique, bending by low-energy electron beam does not cause significant damage and contamination to the nanostructures. Using Monte-Carlo simulations of electron-silica interaction, we show that the upward bending happens when most of the electron energy is absorbed in the upper-half of the cantilever. We also show how the bidirectionality of the bending can be used to restore bent cantilevers to their original orientation (Fig. 2(b)-(c)) by simply choosing a suitable exposure condition. Silica being a common material in semiconductor, MEMS, and nanophotonic devices, this technique can facilitate novel fabrication routes, and mechanisms for post-fabrication shape and mechanical tuning of devices.