Development of Silicon/Sapphire (Si/A12O3) Multilayers for Silicon Based Optoelectronic Applications

In Phase I of this Small Business Innovation Research program we propose to investigate the fabrication of Si quantum well structures for optoelectronic applications, employing Al2O3 (sapphire) as the barrier material. The program will investigate the growth of Al2O3 epilayers on Si, Si epilayers on Al2O3, and elementary Si/Al2O3 multilayers. While Si and Al2O3 have differing crystal symmetries, (zincblende and rhombohedral respectively) the inplance atomic nets in the (111) plane of both crystal structures have the same atomic arrangement, permitting epitaxy of Al2O3 on Si(111) and Si on Al2O3(111). The structures will be grown by molecular beam epitaxy, with Al2O3 synthesized from an elemental aluminum cell and a N2O gas source. The resulting layers and structures will be characterized by a variety of techniques, including x-ray diffraction, energy dispersive x-ray analysis, and magneto hall to assess the crystalline integrity of the layers and heterostructures, and the electrical properties of the Si layers. The Phase I results will be used to assess the potential of this material system for silicon based optoelectronic applications. If successful a silicon optoelectronic device (infrared laser) will be produced in Phase III.