Selective-area epitaxy of GaAs through silicon dioxide windows by molecular beam epitaxy

Abstract

Optical-quality GaAs films were successfully grown by molecular beam epitaxy (MBE) through SiO2 insulator windows on GaAs (100) substrates, thus making this selective-area epitaxy applicable to the fabrication of GaAs optoelectronic integrated circuits. The photoluminescence spectra at 2.2 K consist of several exciton peaks near 820 nm and broader acceptor-related peaks centered at approximately 830 nm. The spectra are comparable to those observed in high quality planar MBE GaAs grown in other laboratories. The luminescence intensity from the epitaxial layer above the windows is shown by cathodoluminescence to be much higher than that from the polycrystalline GaAs deposited on top of SiO2. From transmission electron microscopy and x-ray diffractometry it is found that the GaAs grains on the SiO2 grow with their (111) planes preferentially parallel to the SiO2 surface.