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 This cluster focuses on materials growth and device processing technologies from a systems application viewpoint with compound and organic semiconductors as the focus of study. The growth of these new materials requires an understanding at the molecular level and exploits the quantum effect of nanostructures for device operation. Examples of our research include light-emitting diodes for use in full colour displays, and laser devices that are used in optical data storage and in fibre optic communications. We also undertake specialised characterisation of the optical properties of both materials and devices. In addition to these, materials development for application in sub-micron Si devices is being pursued, specifically in the area of silicides and thin film metallurgy.
 Our optoelectronic devices are built on gallium arsenide (GaAs), indium phosphide (InP) and gallium nitride (GaN)-based compound semiconductors. These materials are applied in colour displays, communications systems and high-speed optoelectronic devices. Metal organic chemical vapour deposition (MOCVD) and molecular beam epitaxy (MBE) are used for the growth of the epilayers that make up the devices. Growth technologies for low dimensional structures ranging from quantum wells to wires and dots have been established and the interplay between strain and heterostructure compositions is being exploited for large lattice mismatch epitaxy. Devices fabricated using our research include semiconductor lasers, light-emitting diodes, vertical cavity surface emitting lasers, infrared detectors, quantum effect devices, photonic switches, HEMTs and HBTs. SiGe is being used in the fabrication of optical components like switches and modulators. Work is also being carried out on exploiting the intrinsic properties of III-V materials by combining electro-optic functions in a MEMS configuration. This work focuses on fabricating freestanding structures like beams, cantilevers and membranes, on GaAs and InP substrates. Another study being conducted is the design and fabrication of InGaAs / InP-based tunable photodetectors with a wavelength window at 1550 nm.
 Research into plastic electronics involves developing new device architectures like organic thin film transistors (OTFT), continuing the development of organic light-emitting displays (OLED) as well as researching on static induction transistors and photodiodes. Plastic electronics are an attractive alternative to current materials, given their flexibility as well as low production cost. OLEDs, for instance, have lower power consumption, higher luminescence, wider viewing angles and a slimmer display when compared to existing liquid crystal display technology. They can also be built on ultrathin, flexible substrates. The OLED research being pursued in IMRE includes barrier property studies of multilayer plastic substrates to reduce moisture and oxygen permeation, degradation of the polymer active layer and carrier injection properties at the metal-polymer interface. New OLED device architecture using polymeric thin film growth techniques is also being investigated. Organic semiconductors may see application in smart-tags for warehouse or supermarket items, books or even plastic cards.
 This research undertaken in IMRE is related to the development of new nickel silicide material for future generation CMOS devices and includes the study of disilicide nucleation, doping effects, mono-silicide agglomeration, inversion phenomenon, and silicide metal gates. Process integration related issues such as defect formation, effects of silicidation on device performance and reliability are also being pursued. Surface treatment of low-k dielectric films so that the top layer would act as a diffusion barrier represents an additional area of study. Because of miniaturisation, another area being looked at in IMRE is the study of thin film metallurgy for opto- and electronic packages that contain lead-free solders. Several concerns, such as thermal barrier design, interfacial reaction between thin films and solders, and electromigration are also being addressed.
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