SELECTIVE GROWTH OF WIRE STRUCTURES OF GAAS ON CAF2 USING FOCUSED ELECTRON-BEAMS

A selective growth method using the surface modification effect on a fluoride surface by electron beam exposure was investigated as a new microfabrication technique. Wire structures of GaAs on CaF2 with 500 nm width were obtained using a 40 keV electron beam at a dose of 2 mu C/cm. The size of these structures was dependent on the dose and energy of the electron beam and thickness of the As film covering the surface of CaF2. From these experimental results and Monte Carlo simulation of injected electrons, it was found that the linewidths of structures were mainly determined by the forward scattering of electrons in the As film. The possibility of obtaining smaller size GaAs using higher energy electron beam and thinner As film is discussed.