ELECTRON-BEAM EXPOSURE EPITAXY (EBE-EPITAXY) FOR THE FORMATION OF SOI-GaAs films on CaF//2/Si(111) STRUCTURES.

A novel heteroepitaxy technique, which we call electron-beam exposure epitaxy (EBE epitaxy), has been employed in growing GaAs films on CaF//2/Si(111) structures. In this method, prior to the growth of GaAs films, the surfaces of CaF//2 are exposed to an electron-beam under impingement of arsenic fluxes. Consequently, thin GaAs films with excellent crystallinity and smooth surfaces could be obtained on the CaF//2/Si(111) structures. The electron beam exposure effect strongly depended upon the electron dose. It has been found that the GaAs films grown by this method have preferentially and dominantly type A orientation which is identical to that of the CaF//2. Cross-sectional transmission electron microscopy has shown that the defect density in the GaAs films is reduced by employing the EBE epitaxy.