来实：放飞创意建筑的设计畅想

2010上海世博会是继北京奥运会后,中国展现给世界的又一个惊喜和盛事。它将成为全世界人民心中又一个难忘的体验。     

Physical and electrical characterization of polysilicon vs. TiN gate electrodes for HfO2 transistors

The effects of pre-deposition substrate treatments and gate electrode materials on the properties and performance of high-k gate dielectric transistors were investigated. The performance of O₃ vs. HF-last/NH₃ pre-deposition treatments followed by either polysilicon (poly-Si) or TiN gate electrodes was systematically studied in devices consisting of HfO₂ gate dielectric produced by atomic layer deposition (ALD). High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) using X-ray spectra and Electron Energy Loss Spectra (EELS) were used to produce elemental profiles of nitrogen, oxygen, silicon, titanium, and hafnium to provide interfacial chemical information and to convey their changes in concentration across these high-k transistor gate-stacks of 1.0–1.8 nm equivalent oxide thickness (EOT). For the TiN electrode case, EELS spectra illustrate interfacial elemental overlap on a scale comparable to the HfO₂ microroughness. For the poly-Si electrode, an amorphous reaction region exists at the HfO₂/poly-Si interface. Using fast transient single pulse (SP) electrical measurements, electron trapping was found to be greater with poly-Si electrode devices, as compared to TiN. This may be rationalized as a result of a higher density of trap centers induced by the high-k/poly-Si material interactions and may be related to increased physical thickness of the dielectric film, as illustrated by HAADF-STEM images, and may also derive from the approximately 0.5 nm larger EOT associated with polysilicon electrodes on otherwise identical gate stacks.     

A simulation tool for dynamically reconfigurable field programmablegate arrays

The emergence of static memory-based field programmable gate arrays (FPGAs) that are capable of being dynamically reconfigured, i.e., partially reconfigured while active, has initiated research into new methods of digital systems synthesis. At present, however, there are virtually no specific CAD tools to support the design and investigation of digital systems using dynamic reconfiguration. This paper reports on an investigation of new CAD tools and the development of a new simulation technique, called dynamic circuit switching (DCS), for dynamically reconfigurable systems. The principles of DCS are presented and examples of its application are described     

Electrochemistry of room-temperature chloroaluminate molten salts at graphitic and nongraphitic electrodes

The electrochemistry of unbuffered and buffered neutral AlCl₃-EMIC-MC1 (EMIC =1-ethyl-3-methylimidazolium chloride and MC1= LiCl, NaCl or KCl) room-temperature molten salts was studied at graphitic and nongraphitic electrodes. In the case of the unbuffered 1 : 1 AlCl₃ : EMIC molten salt, the organic cation reductive intercalation at about –1.6 V and the AlCl₄ ^– anion oxidative intercalation at about +1.8 V were evaluated at porous graphite electrodes. It was determined that the instability of the organic cation in the graphite lattice limits the performance of a dual intercalating molten electrolyte (DIME) cell based on this electrolyte. In buffered neutral 1.1 :1.0:0.1 AIC1₃: EMIC : MCl (MC1= LiCl, NaCl and KCl) molten salts, the organic cation was intercalated into porous and nonporous graphite electrodes with similar cycling efficiencies as the unbuffered 1 : 1 melt; however, additional nonintercalating processes were also found to occur between 1 and –1.6 V in the LiCl and NaCl systems. A black electrodeposit, formed at –1.4 V in the LiCl buffered neutral melt, was analysed with X-ray photoelectron spectroscopy and X-ray diffraction and was found to be composed of LiCl, metallic phases containing lithium and aluminium, and an alumina phase formed from reaction with the atmosphere. A similar film appears to form in the NaCl buffered neutral melt, but at a much slower rate. These films are believed to form by reduction of the AlCl₄ ^– anion, a process promoted by decreasing the ionic radius of the alkali metal cation in the molten salt. The partially insulating films may limit the usefulness of the LiCl and NaCl buffered neutral melts as electrolytes for rechargeable graphite intercalation anodes and may interfere with other electrochemical processes occurring negative of –1 V.