10:30-12:00
Modelling components of future nano-devices
Prof. Alexander Shluger（Department of Physics and Astronomy, the London Centre for Nanotechnology and Materials Simulation Laboratory, University College London, UK）
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Developing novel materials and components for future nano-scale devices is now impossible without extensive computer modelling. We have been involved in several projects dealing with designing and creating molecular and more traditional complementary metal-oxide-semiconductor (CMOS) devices. I will focus on our studies of metallic contacts and the properties of gate oxides and will present new results on the mechanisms of defect processes in oxide and metal nanoclusters and at surfaces using different levels of multi-scale modelling.
First, I will discuss a variety of transient structural features that exist at surfaces of small Au nano-clusters at elevated temperatures. These clusters can serve as metallic contacts in molecular devices and as catalysts where transient low-coordinated sites exhibit enhanced reactivity. I will demonstrate how the structure of these clusters is shaped by ambient gas environment at realistic temperatures.
Designing and fabricating molecular devices requires detailed understanding of the mechanisms of adsorption and diffusion of functional molecules at insulating surfaces and their connection to metallic wires. I will present our recent progress in simulating the mechanisms of adsorption and diffusion of fairly large organic molecules with polar binding groups on the perfect and defective MgO and TiO2 (110) surfaces. I will demonstrate that the structure and flexibility of a molecule has a profound effect on the mechanism of its diffusion and the effective diffusion rate.
Properties of materials used for gate dielectrics will determine the reliability of future CMOS transistors and molecular devices. I will discuss the effects of electron and hole trapping in SiO2 and HfO2 and at grain boundaries in MgO on the properties of new devices, their reliability and breakdown.
