Flux Controlled Sources for Gas Source MBE/CBE Systems

We propose to develop and commercialize a Laser Molecular Beam Epitaxy (LAMBE) source, which will produce a rapidly variable and precisely controlled flux of any elemental source (and many molecular compound sources) in an ultrapure gas flow, for Gas Source Molecular Beam Epitaxy (GSMBE), Metal Organic Molecular Beam Epitaxy (MOMBE), or Chemical Beam Epitaxy (CBE) UHV systems. The LAMBE system uses a 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. The source may be used with easily evaporated elements, such as Zn and As or, more importantly, with those much more difficult to evaporate, such as silicon or carbon. The source design is based upon adaptation of our existing (and patented) Laser Assisted Molecular Beam Deposition (LAMBD) technology, which has been successfully applied to produce films of Cu, metal oxides (TiO2, CuO, Al2O3) and CuI, to form multi-material systems such as high Tc superconducting films, HAP films, and inorganic host/organic dopant films. The source is designed to be retrofittable to commercial systems and compatible with flux (feedback) controlling instrumentation. The development of the proposed source is a natural outgrowth of this existing LAMBD technology. The proposed source benefits from the safety associated with elemental sources combined with the flexibility associated with GSMBE, MOMBE, or CBE systems but with none of the associated hazards of reactant gases such as arsine or silane. Further, it allows the flux regulated use of high temperature elements such as C, Ge and Si among others, which is not possible with any other "valved" source technology.