Si-CeO2 Silicon-On-Insulator Device Structure Grown by Laser Assisted Molecular Beam Deposition

We propose to develop and commercialize a Laser Assisted Molecular Beam Deposition (LAMBD) process for the growth of single crystal lattice matched CeO2 thin films on a Si substrate and thin film Si on CeO2 for the development and commercialization of silicon-on-insulator (SOI) devices and potentially Si based optoelectronic devices. CeO2 is nearly lattice matched to Si (0.35% rnismatched), which offers the possibility for epitaxy growth on Si. SOI devices improve power and speed performance over bulk Si devices. Thus, CeO2 insulators may help in the development of SOI device structures, which have commercial applications for radiation-hardened electronics, optoelectronics, BJTs and BiCMOS. Further, a superlattice of Si-CeO2 quantum well structures could lead to the first practical Si based photon emission structures. In this Phase I effort, we shall demonstrate the growth of CeO2 thin films on a Si substrate using the patented LAMBD technique followed by the deposition of epitaxy Si on the CeO2 film and lastly demonstrate Si-CeO2 quantum well structures. Our LAMBD system uses a patented variable pulsed laser beam to precisely evaporate a source material into a pulsed gas stream, producing a controlled "digital" molecular flux. The flux train can be varied from discrete pulses to effectively a continuous flux. Generic development of LAMBD-CBE technology is presently funded by BMDO/AF. During Phase I, we shall explore the advantages of gas phase reaction chemistry in producing the correct stoichiometry to achieve our desired material structures. A program goal is to also move towards Si-CeO2 multilayer device structures. The.structure of the films shall be characterized by optical spectroscopy, electron microscopy, and XRD to determine the crystallinity of the CeO2 on the Si substrate. Phase II, we will refine our production capabilities and develop applications. Phase m will market material and devices. Our Laser Assisted Molecular Beam Deposition technology combines the advantages of laser ablation and gas phase chemistry to grow CeO2 based thin films. CeO2 thin films on Si have demonstrated near epitaxy growth, which gives strong commercial potential for our effort and for high speed transistors,