9409925 Sadra The P.I. propose a new approach to in-situ patterning in II-V MBE. The P.I. propose to use thermal etch-back, the reverse of the growth process, as an additional degree of freedom in designing the fabrication sequence. Furthermore, we will pattern this etch-back process in-situ. Although several attempts at in-vacuu patterning in MBE have been made, 10-12 the techniques used require complex and expensive multiple-chamber systems and do not offer the full process simplification of a single-chamber in-situ technique. Here, the P.I. propose to develop the capability to perform growth, patterning, etching, and overgrowth, in one chamber, all in a fully automated manner and without removing the substrate from its growth position. The P.I. will employ two approaches to producing the pattern, depending on the desired minimum feature size. For applications requiring resolution no smaller than a few microns, we will use a laser scanning system. For fabrication of quantum wires and dots we will attempt to use natural patterning properties to produce a patterned etch-back mask. Each of these techniques offers its own possibilities and challenges, with the latter having a more exploratory nature than the former. ***
