Downscaling of classical metal oxide semiconductor (MOS) devices resulted in a need to replace the gate oxide by high k dielectrics to keep the gate leakage under control. However, new device issues such as an uncontrollable shift in the threshold voltage in p-type MOS devices and a reduction in channel mobility were encountered. These issues can be overcome by the implementation of buried strained SiGe channels, grown by selective epitaxial growth, as demonstrated in this paper. The optimized high k gate fabrication scheme starts with the growth of a very thin oxide layer. Therefore, a Si cap layer is required because oxidation of SiGe leads to defects at the gate/channel interface. The Si growth rate is influenced by the underlying SiGe layer, during the deposition of the first atomic layers. Nevertheless, accurate thickness control of the Si cap is possible. The minimal required Si cap thickness and its dependence on Ge content in the underlying SiGe channel, for making high-quality dielectrics and maintaining low capacitive equivalent thickness, is extracted from charge pumping measurements, CV measurements and energy dispersive x-ray spectroscopy measurements. Device results demonstrate the successful implementation of buried SiGe channels in pMOS devices with high k gate dielectrics.

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Extremely sharp, uniform, low operation voltage and high integrated field emitter arrays (FEAs) have been developed by the Transfer Metal Mold emitter fabrication technique[l] using ultra precision machining and super microelectroplating technology to realize high efficient and high reliable vacuum microelectronic devices, especially, vacuum microelectronic power switching devices[Z], for the frst time. Transfer Ni FEAs using Cu Master FEAs and Transfer Ni FEA using Ni Master FEA, having high emitter density of 8 million tipslcm', containing 1.31 billion emitter tips, one of the highest value reported in the world to date, have demonstrated the lowest turn-on voltage value of 9.5 VIP m, 14.9 V/p m in the world, respectively. Because of the superior transfer characteristics and the cutting precision by microelctroplating and ultra precision machming, the emitter tip radii of Cu Master FEAs, Ni Master FEAs, and their Transfer Metal Mold Ni FEAS, are as small as 1 Onm.

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Surface morphology and quality of strained InGaAs grown by molecularbeam epitaxy on GaAs Low substrate temperature molecular beam epitaxial growth and the critical layer thickness of InGaAs grown on GaAs Influence of substrate temperature and InAs mole fraction on the incorporation of indium during molecularbeam epitaxial growth of InGaAs single quantum wells on GaAs Lateral variation of In content in a l.5 ,um thick InxGa) _xAs (x=0.2) epilayer grown on channeled GaAs (100) substrates having (755)A or (411)A slope regions by molecular beam epitaxy (MBE) was studied by the energy dispersive x-ray spectroscopy, with high spatial resolution (0.6 ,urn). Significantly peculiar migration of In atoms on the (411)A was observed. Experimental data of this work strongly suggest that In atoms migrate preferentially in one way, that is to say, they migrate much more in the [122] direction than in the opposite [122] direction on the (411)A plane during MBE growth. The migration length of In atoms on the (100) plane was 5 fLm when InGaAs was grown at T,=570 °C and V/III=30.