OCT 4 Colloquia

    As the sizes of microelectronic devices shrink, the surface/interface properties of the film, especially the roughness, play an ever increasing and important role in device fabrications and operations. Therefore, to characterize surface roughness during thin film processing, to understand the origin of the roughness, and to control the degree of roughness, are important tasks for thin film research and microelectronics development. In this talk, I will present how to explore thin film growth mechanisms through the characterization of surface roughness evolution using nanoscale probes and dynamic scaling concept, and their applications in novel nanostructure fabrications. By investigating the roughness evolution of sputtering growth of Si, we realized that Si particle re-emission and shadowing effect may be the dominant effect that controls the morphology evolution, and we proposed a novel re-emission model to explain the observed experimental results. Then I will show a simple way of controlling/fabrication of three-dimensional nanostructures using the glancing angle deposition method. One can fabricate various nanostructures, such as nano-wire arrays with different shapes, nano-spring arrays, and even multilayer nanostructures. This method offers a fullly three-dimensional control of the nanostructure with additional capability of self-alignment, and there is almost no limitation on materials that can be fabricated into desired nanostructures.