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21.
新型高k栅介质材料研究进展 总被引:5,自引:0,他引:5
随着半导体技术的不断发展,MOSFET(metal-oxide-semiconductor field effect transistor)的特征尺寸不断缩小,栅介质等效氧化物厚度已小至nm数量级。这时电子的直接隧穿效应将非常显著,将严重影响器件的稳定性和可靠性。因此需要寻找新型高k介质材料,能够在保持和增大栅极电容的同时,使介质层仍保持足够的物理厚度来限制隧穿效应的影响。本文综述了研究高k栅介质材料的意义;MOS栅介质的要求;主要新型高k栅介质材料的最新研究动态;展望了高k介质材料今后发展的主要趋势和需要解决的问题。 相似文献
22.
虚拟仪器(VI)将计算机采集测试分析引入到电子测量领域,用数字化和软件技术极大地提高了测量的灵活性。而VI远程测控系统是网络技术、通信技术一计算机虚拟技术结合的产物。远程控制技术能够使操作突破地域的限制,已在网络环境下PⅢ工控机上实现。 相似文献
23.
The state of the art of debugging is examined. A debugged process model that serves as the basis of a general debugging framework is described. The relationship of the model to traditional debugging processes and support tools is discussed. A minimal set of requirements for a general debugging framework is described in terms of both the theory behind debugging methodologies and the support tools. An execution monitor, Eden, that serves as a debugging tool within this general framework is described 相似文献
24.
Colour Centres and Energy Transfer in BaF2-xClx:Eu2+ Phosphors 总被引:1,自引:1,他引:0
The optical absorption spectra of BaF2-xClx:Eu2 after ultraviolet (UV) light excitation were investigated.The differences between the absorption spectra after and before excitation (DAS) were observed.The DAS increase at both the high and the low energy side of F band in BaF2-xClx:Eu2 after 245 nm UV light excitation.The bleach effect of UV light and the absorption of electrons in the valence band may account for the former and the formation of Fa centres (association of F(Cl-) centres), whose absorption band matches the HeNe laser better, may explain the latter.In the write-in process, the transfer of electrons is via tunneling.In the readout process, the transfer of electrons captured in F(F-) and Fa centres is more likely via tunneling, and that of F(Cl-) centres is more likely via conduction band. 相似文献
25.
26.
A subspace detection method of analog space-time codes for multiantenna ultra-wideband transmissions
Xiantao Cheng Weile Zhu 《Communications Letters, IEEE》2005,9(6):493-495
In this letter, we propose a subspace based detection method for space-time block codes (STBC) wedded with ultra-wideband (UWB) transmissions. Without the need of channel information, the proposed algorithm yields the estimation of transmitted symbols by minimizing some quadratic form built on the orthogonality between signal and noise subspaces. Simulations in flat-faded application scenarios show that the subspace method can achieve the same diversity and a loss of about 2 dB at the 10/sup -3/ level with more than four successive space-time codes being decoded jointly, compared to the coherent decoding algorithm. 相似文献
27.
Cochannel narrowband interference can limit the performance of direct sequence spread spectrum (DSSS) and high frequency (HF) systems. Narrowband interference (NBI) can be single tone, chirped or frequency shift keyed (FSK) in nature and numerous techniques for its removal have been proposed. Linear adaptive prediction filters based on autoregressive modelling have been suggested owing to their ability to perform in a non-stationary environment. In the FSK narrowband interference case, adaptive filters are susceptible to excess residual errors owing to instantaneous frequency step changes and the finite convergence time required for the filter to adapt to a new interference frequency. The signal degradation owing to this type of interference becomes greater in high SNR regimes and has been found to be a function of the frequency parameters of the FSK interference signal. The paper discusses the convergence and frequency tracking properties of the recursive least squares (RLS) adaptive lattice filter using a posteriori estimation errors in the presence of FSK narrowband interference. An optimal exponential weighting factor that balances convergence time and steady state error is derived for this case of NBI. Results are compared to those of a previously proposed fast converging minimum frequency error (FCMFE) RLS lattice filter. 相似文献
28.
Hsing-Chung Liang Wen-Chin Ho Ming-Chieh Cheng 《Reliability, IEEE Transactions on》2005,54(2):358-365
In this paper, we discuss some strategies for identifying unrepairable memories, and from that to introduce a novel theorem that can make more precise identification. A new algorithm for searching repair solutions is also proposed, which characterizes the rows, and columns of defective memory cells with revised effective coefficients. We have simulated it on many generated example maps, and compared it with the previous algorithms to verify its efficiency. It's combined with those arranged strategies of judging unrepairability to generate a complete flow. The complete algorithm has also been run on many examples with various memory sizes, defect numbers, and distribution types. The simulation results further show that identifying unrepairability in advance can help the reconfiguration procedure run much faster than searching solutions directly. 相似文献
29.
A new frequency notched ultra-wideband microstrip slot antenna with a parasitic tuning stub is proposed. The antenna is similar in configuration to a conventional microstrip slot antenna; by introducing a parasitic open-circuit tuning stub, flexible frequency notched function is achieved. Several properties of the antenna, such as frequency notched function, antenna transfer function and gain, have been investigated. As is reported, the operation bandwidth of the antenna is 2.91-11.16 GHz, in which a frequency notched band of 5.10-5.85 GHz has been achieved. Furthermore, good ultra-wideband linear transmission performance over the entire operation frequency range has also been achieved. 相似文献
30.
介绍了子午轮胎硫化的各种介质性能要求及介质供应工艺流程,分析了各种介质的质量要求.介绍了系统各参数的控制调节项目及运行技术管理的一些措施. 相似文献