The funds from the Presidential Young Investigator program will be used to explore the possibility of a Focused Ion Beam Epitaxy System. This would result in the combination of the vertical resolution of the MBE with the lateral resolution of the focused ion beam apparatus, allowing both the fabrication of advanced devices, and the creation of semiconductor structures which allow more direct investigation of physical processes which occur in quantum wells and other quantum sized structures. A short list of the projects which could be centered about such an apparatus includes quantum tunneling devices, study o mechanisms important in hot electron transport, resonant tunneling transistors, active layer modulation distributed Bragg reflection lasers, surface emitting lasers, and three dimensional integrated circuits.