A MULTICHAMBER SYSTEM FOR INSITU LITHOGRAPHY AND EPITAXIAL-GROWTH OF GAAS

A novel multichamber system for beam-assisted etching, in situ lithography, and molecular-beam epitaxy (MBE) has been constructed and proved to be usable with full functions. This system comprises seven ultrahigh-vacuum (UHV) chambers connected by UHV tunnels. A specially designed gun column, which can be used for a focused-ion-beam (FIB) gun or an electron-beam gun, and an introduction system of Cl2 gas have been installed in a UHV chamber for beam-assisted Cl2 gas etching. In order to evaluate the induced damage by ion irradiation, the FIB gun with a novel retarding system was installed. An in situ Auger electron spectroscopy apparatus and an in situ photoluminescence unit were attached to the analysis chamber in order to evaluate the surface composition and the induced damage, respectively. Examples of GaAs/AlGaAs heterostructure grown on in situ patterned substrates showed good surface morphology, indicating the usefulness of this technique for microfabrication.