单声道/立体声录放芯片MSM9841及其在数字语音录放机中的应用

MSM9841是日本OKI(冲)电气半导体公司研制的单声道／立体声语音控制处理大规模集成芯片。文中介绍了该芯片的结构、特点、工作原理及其在数字语音录放机中的应用。     

AlxZn1-xO合金MSM光电探测器的研究

在Si衬底上磁控溅射制备AlxZn1-xO(AZO)合金薄膜,在其上真空蒸发Ni/Au叉指电极获得金属-半导体-金属(MSM)结构光电探测器.采用UV-Vis-Nir分光光度计测量AZO系列薄膜的光吸收特性,观察到AZO 合金薄膜的光学吸收带边随Al含量增加明显蓝移.测试AZO探测器的电流电压特性、时间特性和响应光谱发...     

94K低温下和室温下GaN基MSM紫外光探测器性能的比较

在采用MOCVD技术生长的GaN膜上制备出MSM紫外光探测器，分别在室温下和94K低温下，测量了探测器对不同光波长的响应、同一光波长下对不同偏压的响应、不同斩波频率下的响应。结果表明，在94K下响应有了很大的改善。当光波长从360nm增加到450nm时，响应下降了3个数量级，而常温下只下降两个数量级，但探测器的时间响应常数变长了。     

Defect state assisted tunneling in intermediate temperature molecular beam epitaxy grown GaAs

Current transport in molecular beam epitaxy (MBE) GaAs grown at low and intermediate growth temperatures is strongly affected by defects. A model is developed here that shows that tunneling assisted by defect states can dominate, at some bias ranges, current transport in Schottky contacts to unannealed GaAs material grown at the intermediate temperature range of about 400°C. The deep defect states are modeled by quantum wells which trap electrons emitted from the cathode before re-emission to semiconductor. Comparison of theory with experimental data shows defect states of energies about 0.5 eVbelow conduction band to provide the best fit to data. This suggests that arsenic interstitials are likely to mediate this conduction. Comparison is also made between as-grown material and GaAs grown at the same temperature but annealed at 600°C. It is suggested that reduction of these defects by thermal annealing can explain lower current conduction at high biases in the annealed device as well as higher current conduction at low biases due to higher lifetime. Quenching of current by light in the as-grown material can also be explained based on occupancy of trap states. Identification of this mechanism can lead to its utilization in making ohmic contacts, or its elimination by growing tunneling barrier layers.     

单纯形最优化法介绍

本文简要介绍了在分析化学领域中得到广泛应用的单纯形最优化法,主要是基本单纯形法和改进型单纯形法。     

10 Gb/s OEIC optical receiver front-end and 3.125 Gb/s PHEMT limiting amplifier

A 10 Gb/s OEIC (optoelectronic integrated circuit) optical receiver front-end has been studied and fab ricated based on the φ-76 mm GaAs PHEMT process; this is the first time that a limiting amplifier (LA) has been designed and realized using depletion mode PHEMT. An OEIC optical receiver front-end mode composed of an MSM photodiode and a current mode transimpedance amplifier (TIA) has been established and optimized by simu lation software ATLAS. The photodiode has a bandwidth of 10 GHz, a capacitance of 3 fF/μm and a photosensitive area of 50×50 μm~2. The whole chip has an area of 1511×666 μm~2. The LA bandwidth is expanded by spiral inductance which has been simulated by software HFSS. The chip area is 1950×1910μm~2 and the measured results demonstrate an input dynamic range of 34 dB (10-500 mVpp) with constant output swing of 500 tnVpp.     

A monolithic, standard CMOS, fully differential optical receiver with an integrated MSM photodetector

This paper presents a realization of a silicon-based standard CMOS, fully differential optoelectronic inte grated receiver based on a metal-semiconductor-metal light detector (MSM photodetector). In the optical receiver, two MSM photodetectors are integrated to convert the incident light signal into a pair of fully differential photo generated currents. The optoelectronic integrated receiver was designed and implemented in a chartered 0.35 μm, 3.3 V standard CMOS process. For 850 nm wavelength, it achieves a 1 GHz 3 dB bandwidth due to the MSM pho todetector's low capacitance and high intrinsic bandwidth. In addition, it has a transimpedance gain of 98.75 dBΩ, and an equivalent input integrated referred noise current of 283 nA from 1 Hz up to -3 dB frequency.     

MSM结构ZnO紫外探测器的制备与性质

采用射频磁控溅射在石英衬底上制备了c轴择优取向的ZnO薄膜,利用蚀刻技术制备了MSM结构的光导型紫外探测器。在3V偏压下,器件的暗电流小于250nA,光响应峰值在370nm,响应度是0.34A/W。其紫外(360nm)与可见光(420nm)的抑制比为4个数量级。器件的光响应时间上沿仅为20ns。     

A scale‐free network model for HIV transmission among men who have sex with men in China

Objective: The study aimed to analyze sexual networks and sex role preference as factors of HIV transmission among men who have sex with men (MSM) in China. Methods: We have developed a new scale‐free network model with a sex role preference framework to study HIV transmission among MSM. We have studied the influence of different sexual networks and the effect of different proportion of sex role preference upon HIV transmission. The results are that the average ones drawn from the scenarios have been simulated for more than 30 times. Results: Compared with the traditional mathematical model, the sexual networks provide a different prediction of the HIV transmission in the next 30 years. Without any intervention, the proportion of HIV carriers will descend after some time. Conclusions: There is significant associations among network characteristics, sex role preference, and HIV infection. Although network‐based intervention is efficient in reducing HIV transmission among MSM, there are only few studies of the characteristics of sexual network, and such gaps deserve more attention and exploration. Copyright © 2016 John Wiley & Sons, Ltd.     

GaN基紫外光探测器的研究进展

相对于其他类型的探测器,GaN基紫外光探测器具有很多优点.本文主要介绍了近几年GaN基紫外光探测器的发展,并对各种结构形式进行了比较.