低温下载流子冻结对CMOS器件特性的影响(英文)

<正> Cryogenic CMOS circuits provide a great promise at very high speed operation because of the enhanced mobility of the carriers at low temperature. However, at low temperature, part of the impurities in Si will not be ionized because the Fermi level moves toward the bottom of conduction band(n-Si) or the top of the valence band(p-Si). In the channel region of MOSFET, the freezeout of the carriers is determined not only by the temperature but also the band bending caused by the gate voltage. In this paper, the effects of carrier freezeout on the characteristics of cryogenic CMOS devices are investigated through a numerical simulation and the measurement of device I-V characteristics at liquid nitrogen temperature. It is found that, at 77K, the impurities in the channel region of the surface channel device are completely ionized while that of the burried channel     

测井资料在大村煤层气勘探中识别煤体结构方法初探

针对煤层样品采集难度大、煤体结构不完整的问题,在加强煤层取芯技术的同时,以三侧向电阻率测井、井径测井、散射伽马测井为主,辅助利用自然伽马测井和声波时差测井等资料,对工区C25煤层煤体结构分别归纳了:I类煤(块煤)、II类煤(块粉煤)、III类煤(粉煤)的测井响应特征。应用结果表明,利用测井曲线组合方法识别煤体结构效果良好,对今后该区煤层气勘探开发有重要参考价值。     

汽轮机微机电调装置介绍

一、引言微型计算机,因其可靠性高、价格日趋便宜、体积小以及具有智能化等无可比拟的优点,而在各个领域中获得了越来越广泛的应用。用微机对各类系统进行控制已成为当今自动控制行业的主要研究课题之一。     

双栅MOSFET高频特性的实验研究

设计制作了不同沟道长度、栅材料以及栅电极构形的各种双栅MOSFET。通过实验全面研究了设计和工艺参数对器件高频特性的影响,阐明了双栅MOSFET的高频设计思想,给出了全离子注入高频低噪声工艺。有效沟道长度为1μm的超高频双栅MOSFET在900MHz下功率增益为17dB,有效沟道长度为1.5μm的甚高频器件在200MHz下功率增益为23dB.