We have evaluated the thermal conductivity of Si/SiGe superlattice films by theoretical analysis and experiment. In experiments, the ultrahigh vacuum chemical vapor deposition is employed to form the Si/ Si 0.71 Ge 0.29 and Si/ Si 0.8 Ge 0.2 superlattice films. The cross-plane thermal conductivities of these superlattice films are measured based on the 3 method. In the theoretical analysis, the phonon transport in Si/ Si 1−x Ge x superlattice film is explored by solving the phonon Boltzmann transport equation. The dependence of the thermal conductivity of the Si/ Si 1−x Ge x superlattice films on the superlattice period, the ratio of layer thicknesses, and the interface roughness is of interest. The calculations show that when the layer thickness is on the order of one percentage of the mean free path or even thinner, the phonons encounter few intrinsic scatterings and consequently concentrate in the directions having high transmissivities. Nonlinear temperature distributions are observed near the interfaces, arising from the size confinement effect and resulting in a slight increase in the film thermal resistances. The interface resistance due to the interface scattering/ roughness, which is nearly independent of the film thickness, nonetheless dominates the effective thermal conductivity, especially when the superlattice period is small. Finally the experimental measurements agree with the theoretical predictions if the specular fraction associated with the interface is properly taken.

No abstract

No abstract

We report the first demonstration of a self-aligned contact technology for III-V MOSFETs. A novel epitaxy process with insitu surface treatment was developed to selectively form a thin continuous germanium-silicon (GeSi) layer on gallium arsenide (GaAs) source and drain (S/D) regions. By precisely and fully converting the GeSi layer into NiGeSi, while diffusing Ge and Si into GaAs to form heavily n + doped regions, a novel self-aligned nickel germanosilicide (NiGeSi) ohmic contact was achieved. This is expected to significantly enhance the performance of III-V MOSFETs.

This paper reports a novel microfluidic chip integrated with molecular imprinting polymers (MIP) for surface plasmon resonance (SPR) detection of specific label-free bio-samples. The innovative microfluidic biochip is capable of transporting a specific amount of bio-samples inside ' multiple microchannels using micropumps/microvalves to sensing regions where multiple MIP films are locally deposited such that highly -sensitive, highly-specific bio -sensing could be achieved. With the help of SPR sensing techniques, the microfluidic biochips have the potential to be widely used for bio-sensing applications. While compared to other sensing techniques, the developed system has several advantages, including labeling-free, high sensitivity, capability of quantitative analysis of nano-scale bio-molecules in reakime fashion.