一种能提高DRC友好性和CMP形貌的冗余金属填充方法

化学机械研磨(CMP)被广泛用于铜镶嵌工艺,研磨后铜的厚度和表面形貌对65纳米以下的工艺显得越来越重要,厚度和形貌的变动会对芯片良率和性能造成恶劣影响,所以必须在设计时就进行慎重的考虑。众所周知,插入冗余金属是提升CMP形貌的一个好方法,通常基于规则的方法广泛用于65纳米及以上工艺中,但是该技术在比较先进制程中显示不出其优越性。本文阐述了一种基于模型的冗余金属填充方法,它是根据设计版图中的周围环境用计算机算法来填充。这一方法的优点有以下几方面:在设计规则检查(DRC)中更少的违规数量,更密集的图形密度分布和更少的填充图案数量,更小的密度和周长梯度。在使用40纳米工艺的晶圆上,基于模型方法得到的表面平坦度与基于规则的填充方法相当,但是比公开的其它填充方法要好。     

Design of a Compact Ka-band Balanced Mixer Based on a Novel Wide-band Equivalent Circuit of the Schottky Diode

A compact Ka-band balanced mixer based on a novel Schottky diode model is presented in this paper. According to its physical structure, a novel 3D electromagnetic model of the Schottky diode is proposed. Meanwhile, a wide-band equivalent circuit is built, which takes all high frequency effects existing in the diode into account. All the parasitic reactances are extracted from the electromagnetic model-based S-parameters up to 110 GHz. Based on the proposed equivalent circuit, a Ka-band balanced mixer is designed and optimized, where bandpass filters with open stubs and a lowpass filter based on defected ground structure cells are used. The measured results show that the conversion loss is below 9 dB from 30 GHz to 40 GHz with the minimum of 6.7 dB at 35 GHz. The normalized size of the mixer is only 3.3λ _g  × 3.3λ _g , whereλ _g is the wavelength at 35 GHz.     

Study of proton irradiation effects on AlGaN/GaN high electron mobility transistors

AlGaN/GaN high electron mobility transistors (HEMTs) were exposed to 3 MeV protons at fluences of 6 × 10¹³, 4 × 10¹⁴ and 1 × 10¹⁵ protons/cm². The drain saturation currents decreased by 20% and the maximum transconductance decreased by 5% at the highest fluence. As the fluence increased, the threshold voltage shifted more positive values. After proton irradiation, the gate leakage current increased. The Schottky barrier height changed from 0.63 eV to 0.46 eV, and the ideality factor from 2.55 to 3.98 at the highest fluence. The degradations of electrical characteristics of AlGaN/GaN HEMTs are caused by displacement damages induced by proton irradiation. The density of vacancies at different proton fluence can be calculated from SRIM. Being an acceptor-like defect, the Ga vacancy acts as a compensation center. While N vacancy acts as a donor. Adding the vacancies model into Slivaco device simulator, simulation results match well with the trends of experimental data. Hall measurement results also indicate the concentration and mobility of 2DEG decrease after proton irradiation. It is concluded that the Ga vacancies introduced maybe the primary reason for the degradation of AlGaN/GaN HEMTs performance.     

日立7180E生化分析仪电解质模块性能评价指标的研究

目的：评价日立7180E自动生化分析仪电解质模块测定K＋,,Na＋,Cl-离子的精密度、稳定性、线性和携带污染率。方法：采用日立公司配套试剂和病人血清,用该仪器测定K＋,Na＋,Cl-离子,对精密度、稳定性、线性及携带污染率等指标进行了评价。结果：批内及稳定性的变异系数均小于1%,批间变异系数均小于1.5%,携带污染率...     

Molecular beacon based bioassay for highly sensitive and selective detection of nicotinamide adenine dinucleotide and the activity of alanine aminotransferase

We have developed a new approach to detect nicotinamide adenine dinucleotide (NAD(+)) with high specificity and sensitivity using molecular beacons (MBs) and employed it in the investigation of NAD(+) related biological processes, such as calorie restriction and alanine aminotransferase (ALT) activation. The E. coli DNA ligase would catalyze the ligation of two short oligonucleotides that complement with an MB only in the presence of NAD(+), resulting in the opening of the MB and the restoration of fluorescent signal. Thanks to the high sensitivity of the MB probe and the fidelity of E. coli DNA ligase toward its substrates, this approach can detect 0.3 nM NAD(+) with high selectivity against other NAD(+) analogs. This novel assay can also provide a convenient and robust way to analyze NAD(+) in biological samples such as cell lysate. As NAD(+) plays an essential role in many biochemical processes, this method can be used to investigate NAD(+) related life processes. For instance, the effect of calorie restriction on the intracellular NAD(+) level in MCF7 cells has been studied using this new assay. Moreover, this approach was also successfully used to analyze the activity of ALT. Therefore, this novel NAD(+) assay holds wide applicability as an analytical tool in biochemical and biomedical research.     

Implementation of tridirectional large lateral shearing displacement interferometry in temperature measurement of a diffused ethylene flame

A tridirectional large lateral shearing displacement interferometric system has been proposed and used to reconstruct the temperature field of a quasi-axisymmetric diffused ethylene flame in two-dimensional (2D) and three-dimensional (3D) hypotheses. In comparison with the thermocouple results, the 2D reconstructed results affords a quantitative analysis with an average discrepancy between 20 and 40 K in the full field, except in the closer part inside the peak temperature location where a high soot volume fraction exists. The 3D reconstructed results affords qualitative analysis and exhibits some asymmetrical characters, but an obvious error occurs at 1 cm height where it is not suitable to use the universal correction coefficient.     

文化区位视野下的河西乡土建筑现象解析

从分析河西走廊地区的文化区位入手,探讨了区域性地域文化与乡土建筑的深层关联,进而勾勒出特定文化环境中建筑生成的有机图景。论文总结了文化区位事实与乡土建筑现象之间的密切联系,指出河西特色文化对其乡土建筑的形成、发展形成起到了重要的影响作用,对今后广大河西走廊乡土建筑文化建设具备一定的启发意义。     

盒子与空间——玛莎·舒瓦茨的设计理念与实践

通过回顾2011年4月在西安建筑科技大学举办的对话世园会风景园林大师活动中玛莎·舒瓦茨(Martha Schwartz)的精彩报告,管窥其设计理念及该理念指导下的实践项目,了解当代先锋风景园林设计大师的设计思想及方法,从中得到对于正在起步中的中国园林学科设计及教育方面的启示与引导。     

基于GIS技术的滑坡群影响因子分析与评价

GIS技术在滑坡评价中得到了广泛应用,为解决滑坡的影响因子识别和危险性预测等提供了有效手段.本次研究借助GIS技术平台,建立三峡库区某滑坡群空间分布模式、识别滑坡发育影响因子,判定滑坡发育阶段,最后基于GIS技术评价滑坡稳定性.研究结果表明,GIS能够有效快速的解决滑坡评价的有关问题,且该滑坡群发生的主要影响因子是岩土...     

APU冷却通风系统温度测量与分析

通过加装在辅助动力装置（APU）舱内和APU附件表面的温度传感器对舱温和附件表面温度测量,研究了一个典型的飞行剖面各温度变化情况。测试数据分析表明,舱内测点的最高温度值都是出现在地面利用APU启动主发时。当APU存在电负载和气负载时,环境温度和附件表面温度比不带负载会有5℃左右的上升。另外,较小的飞行速度对APU舱的冷却通风是有利的,但随着速度的继续增大,冷却通风效果变差。