Solid State Phenomena Vols. 121-123

Abstract: In this paper, it is presented that flicker (1/f) noise of ultra thin gate oxide can be improved by initial oxidation and subsequent plasma nitridation(PN). PN which raises Nitrogen peak upward from the Si/Oxide interface to gate polysilicon/Oxide interface is adopted mainly to improve the life time such as Negative-Bias Temperature Instability (NBTI) and hot carrier in Nano CMOS technology. Three different types of initial oxidation prior to plasma nitridation are investigated. One is slow thermally grown oxide(STO) in very small Oxygen ambient, another is rapid thermally grown oxide(RTO) and the other is grown in Nitrous oxygen ambient (NO). Oxide thickness of all splits is about 14.5< Then, it is shown that STO has the lowest drain current noise power (Sid) among the splits. The interface trap densitie (Dit) of each oxide is characterized using charge pumping method. Finally, we reached a conclusion that the 1/f noise can be significantly reduced by initial STO and Plasma Nitridation in Nano CMOS technology.

Abstract: A numerical method based on Finite Difference Time Domain (FDTD) scheme for computing the photonic band-structure of three dimensional photonic crystals is introduced in this paper. Also, the accuracy and stability, numerical dispersion, boundary Conditions as well as excitation attaching to the scheme are detailed analyzed. For checking the method, the simulating results of photonic band structure on two type lattices are presented.

Abstract: In order to realize active grinding control, a nanometer micropositioning table is designed. The table has a circular working area with diameter of 150 mm. Three piezoelectric actuators are utilized in parallel to drive the moving part with flexure guide mechanism. Through cooperation of the three piezoelectric actuators, the moving part can implement 3-DOF nanometer positioning. The flexure hinge mechanism can also provide preload for the actuators. The preload can keep the moving part from separation with the piezoelectric actuators during moving process. The dynamic model of the micropositioning table is developed with consideration of the driving circuit. To improve the dynamic performance of the micropositioning table, a decoupling PID controller is designed by use of frequency domain approach. The experimental tests have been carried out to verify the performance of the micropositioning table and the established decoupling controller.

Abstract: The Monte Carlo(MC) and Embedded-Atoms Method(EAM) potential are employed to investigate the structures and binding energies of copper clusters. Three results are obtained: first, the copper clusters are formed by gradually increasing atoms to icosahedral surface when the temperature is 300K and the number of atoms is from 2 to 70; second, the higher the symmetries are, the more stable the structures of copper clusters are; third, copper clusters tend to be stereo construction but not planer construction when the number of atoms is less. The structure of Cu147 is three-fly-icosahedron when the system of 147 atoms reached equilibrium at 300K. And at 700K, all 500 atoms form clusters in gas phase.

Abstract: This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.

Abstract: Meso- piezoresistive effect is proposed, which is defined as “Strain Tuning of the resonant current”, in order to convert a weak mechanical signal into a strong tunneling current signal. If a mechanical signal is acted on an related mechanical nano-structure, the corresponding strain distribution will be produced in the structure; the built- in electric field will be resulted from the strain in system in some conditions; the strain and built-in electric filed will result in the change of electronic energy states; the change of electronic energy state will influence on the value of the tunneling current. Two experimental units are designed, one being used to detect an acoustic signal under sea, other to detect acceleration.

Abstract: In this paper, novel Ni Germanosilicide technology using the 1%-nitrogen doped Ni and pure Ni stack structure has been proposed for nano-scale CMOS technology. The Ni Germanosilicide is formed on the Si0.8Ge0.2 layer which is known as an optimal composition for strained silicon application. Proposed structure showed much better thermal stability than pure Ni case. Silicide characteristics such as the sheet resistance, the interface uniformity of silicide/SiGe, surface roughness, and depth profile of the Ni, Si, and Ge showed little degradation even with the high temperature post-silicidation annealing at 600
for 30 min. Therefore, the proposed method is highly promising for nano-scale CMOS technology.

Abstract: Liquid phase deposition (LPD) grown InGaP native oxide near room temperature (~60oC) is demonstrated and investigated for the first time. A high oxidation rate (~80nm/hr) is obtained and checked by SEM and AES. The oxide is determined to be composed of InPO4 and Ga2O3 which are analyzed by the results of XPS measurement. Due to the presence of excellent quality of InGaP native oxide, high hydrogen (H2) sensitivity in output current of Pd/oxide/InGaP MOS Schottky diode is observed. Under the applied voltage of -1V and 50ppm H2/air, a high sensitivity of 1090 is obtained. In addition, an obvious variation of output current and a short response time due to the exposure to different H2 concentration are also achieved.

Abstract: Single-wall Carbon nanotubes (SWNTs) bonded with dodecylamine groups were obtained by chemical modification. The modified SWNTs showed improved solubility in organic solvents. Both its chemical and aggregated structure was characterized by means of FTIR and TEM. The photoconductivity of oxotitanium phthalocyanine (TiOPc) doped with the modified SWNTs was investigated by xerographic photoinduced discharge method. The results showed that the photosensitivity of the double-layered photoreceptor composed of the SWNTs/TiOPc composite as charge generation material was higher than that of pristine TiOPc, and the sensitivity increased with the content of modified SWNTs in the composites. It is the photoinduced charge transfer between TiOPc and SWNTs that contributes to the improved photosensitivity of the modified SWNTs/TiOPc composites.