This Special Issue is dedicated to recent research in the field of compact modeling of semiconductor devices. This is the first J-EDS Special Issue on compact modeling. In the last years, a number of ...new semiconductor device structures, for electronic and photonic applications, have been developed. Compact models are needed for the incorporation of these new devices in integrated circuits. Therefore, a Special Issue was needed to present recent compact modeling solutions for semiconductor devices
Based on measured four-noise parameters and two-port noise theory, considerations for noise optimization of integrated low-noise amplifier (LNA) designs are presented. If arbitrary values of source ...impedance are allowed, optimal noise performance of the LNA is obtained by adjusting the source degeneration inductance. Even for a fixed source impedance, the integrated LNA can achieve near NF/sub min/ by choosing an appropriate device geometry along with an optimal bias condition. An 800 MHz LNA has been implemented in a standard 0.24 /spl mu/m CMOS technology. The amplifier possesses a 0.9 dB noise figure with a 7.1 dBm third-order input intercept point, while drawing 7.5 mW from a 2.0 V power supply, demonstrating that the proposed methodology can accurately predict noise performance of integrated LNA designs.
Cancer cells undergo a number of biophysical changes as they transform from an indolent to an aggressive state. These changes, which include altered mechanical and electrical properties, can reveal ...important diagnostic information about disease status. Here, we introduce a high-throughput, functional technique for assessing cancer cell invasion potential, which works by probing for the mechanically excitable phenotype exhibited by invasive cancer cells. Cells are labeled with fluorescent calcium dye and imaged during stimulation with low-intensity focused ultrasound, a non-contact mechanical stimulus. We show that cells located at the focus of the stimulus exhibit calcium elevation for invasive prostate (PC-3 and DU-145) and bladder (T24/83) cancer cell lines, but not for non-invasive cell lines (BPH-1, PNT1A, and RT112/84). In invasive cells, ultrasound stimulation initiates a calcium wave that propagates from the cells at the transducer focus to other cells, over distances greater than 1 mm. We demonstrate that this wave is mediated by extracellular signaling molecules and can be abolished through inhibition of transient receptor potential channels and inositol trisphosphate receptors, implicating these proteins in the mechanotransduction process. If validated clinically, our technology could provide a means to assess tumor invasion potential in cytology specimens, which is not currently possible. It may therefore have applications in diseases such as bladder cancer, where cytologic diagnosis of tumor invasion could improve clinical decision-making.
Due to the offset in the valence band, strained-Si nMOSFETs exhibit a -100 mV threshold shift and 4% degradation of the subthreshold slope per each 10% increase of Ge content in the relaxed SiGe ...layer. The correlation between the threshold shift and strained layer thickness is investigated based on device simulations. In a certain range of the strained-Si layer thickness, the threshold and subthreshold slope change gradually, posing a concern of larger device parameter variation. A larger threshold distribution is observed in devices fabricated with a strained layer thickness comparable to the depletion depth.
Accurate prediction of device aging plays a vital role in the circuit design of advanced-node CMOS technologies. In particular, hot-carrier induced aging is so complicated that its modeling is often ...significantly simplified, with focus limited to digital circuits. We present here a novel reliability-aware compact modeling method that can accurately capture the full post-stress I-V characteristics of the MOSFET, taking into account the impact of drain depletion region on induced defects.
A new eco-friendly synthetic method for N-hydroxysuccinimide (NHS), widely used in the pharmaceutical and fine chemical industries, is developed. Conventional synthesis method yields NHS of about 70% ...after its reaction with NH2OH to succinic acid. In this method, NHS can be obtained using low-cost succinic acid, but a great deal of solvents are required as an extraction method to purify NHS, while the work-up process is complicated, resulting in low yield. In addition, there is a safety risk due to the high reaction temperature for commercial production, and it is not economical due to the high cost of production from the generation of much waste because of an acid catalyst and the use of various solvents. In order to make up for this shortcoming, this study used succinic anhydride as a raw material under low temperature reaction and developed a new eco-friendly industrial synthesis method using isobutyl alcohol for a single solvent and non-catalytic reaction. The economic evaluation confirms that there is a cost reduction effect of about 20%. In the future, based on this result, studies may establish a commercial production technology through scale-up research and proceed with foreign technology transfer. 제약화학 및 정밀화학 산업에서 널리 사용되는 N-히드록시숙신이마이드(N-Hydroxysuccinimide, NHS)의 새로운 친환경적인 합성법을 개발하였다. 기존 합성법은 숙신산에 히드록시아민 반응 후 강산을 촉매로 약 70%의 수율로 NHS를 얻는다. 이 방법은 저가 숙신산을 사용하여 NHS를 얻을 수 있으나 NHS를 정제하는 데에 많은 용제가 필요하고 후처리 과정이 복잡하여 수율이 낮은 문제점이 있다. 그리고 대량생산하기에는 고온반응에 따른 안전상의 위험성이 있으며 산성 촉매를 사용함에 따른 많은 폐기물 발생과 다양한 용제를 사용함에 따라 고비용의 생산비로 인해 경제적이지 않다. 이런 단점을 보완하기 위해서 반응성이 우수한 무수 숙신산을 사용하였으며 용제의 단일화 그리고 결정화 방법을 통해 고순도 및 고수율의 NHS를 제조하는 경제적인 방법을 개발하였다. 특히 촉매를 사용하지 않는 무촉매 반응과 저온의 반응조건을 확보함으로써 80% 이상의 높은 수율로 NHS를 제조하는 새로운 친환경적인 공업적인 합성법이다. 향후에는 이 결과를 바탕으로 스케일 업 연구를 통해 상용화 생산기술을 확립하여 국외 기술이전을 추진할 예정이다.
Strained-Si nMOSFETs with a standard polysilicon gate process were fabricated down to 25 nm gate length with well-behaved characteristics and small difference in short channel effects. The ...performance enhancement degrades linearly as the gate length becomes shorter, due to not only the parasitic resistance but also heavy halo implant. Thus the key integration issues are how to manage threshold difference and As diffusion without excess doping. With comparable doping and well controlled parasitic resistance, up to 45% improvement in drive current is predicted for sub-50 nm gate length strained-Si nMOSFETs on the Si/sub 0.8/Ge/sub 0.2/ substrate. In this work approximately 45% enhancement is in fact demonstrated for 35 nm gate length devices, through advanced channel engineering and implementation of metal gates.
Based on an active transmission line concept and two-dimensional (2-D) device simulations, an accurate and computationally efficient simulation technique for high frequency noise performance of ...MOSFETs is demonstrated. Using a Langevin stochastic source term model and small-signal equivalent circuit of the MOSFET, three intrinsic noise parameters (/spl gamma/, /spl delta/, and c) for the drain noise and induced gate noise are calculated. Validity and error analysis for the simulation are discussed by comparing the simulation results with theoretical results as well as measured data.
A reconstruction technique of the gate capacitance from anomalous capacitance-voltage (C-V) curves in high leakage dielectric MOSFETs is presented. An RC network is used to accommodate the ...distributed nature of MOSFETs and an optimization technique is applied to extract the intrinsic gate capacitance. Applicability of the method is demonstrated for ultra-thin nitride/oxide (N/O /spl sim/1.4 nm/0.7 nm) composite dielectric MOSFETs.
PDF
