Accessing in situ relevant information on the fluctuations in length and covered area fraction at the μm scale of vertical nanowire ensembles by polarization resolved optical reflectometry.
Self-assembled InAs elongated nanostructures were fabricated by continuous processing steps, starting from self-assembling of quantum dots, thin capping over the quantum dots to induce an anisotropic strain field, and to anneal the quantum dots in the molecular-beam-epitaxy machine. In-situ RHEED observations at each processing step were studied and confirmed by ex-situ AFM images of the surface morphology. The elongated nanostructures were demonstrated tobe templates for chains of uniform quantum dots.
The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.
Influence of the source arrangement on shell growth around GaN nanowires in molecular beam epitaxy