MOD－SnO_2酒敏元件研制

采用金属有机物热分解（ＭＯＤ）法制备了ＳｎＯ_２酒敏元件，ＸＲＤ和ＡＥＳ谱表明热处理后己酸亚锡已转化为ＳｎＯ_２。此外还证实ＳｎＯ_２元件的内电势是加热丝偏位引起的热电势。元件的主要技术指标为：灵敏度＞８，选择性＞６，响应时间＜５ｓ，恢复时间＜３０ｓ。     

激光CVD制备SnO_2薄膜的结构及其反应机理研究

采用ＳｎＣｌ４和Ｏ２为反应源，ＡｒＦ准分子激光ＣＶＤ生长ＳｎＯ２薄膜，利用ＸＲＤ、ＵＶＴ、ＸＰＳ研究了薄膜的组成和结构，实验表明ＳｎＯ２薄膜属于四方晶系、金红石结构，薄膜的紫外可见光透射率大于９０％，吸收边波长为３５５ｎｍ，禁带宽度为３．４９ｅＶ。最后，对ＳｎＯ２薄膜的反应机理进行了讨论     

微机软故障检修三例

微机软故障检修三例蔡长安１．例一故障现象：一台４８６ＤＸ２／６６计算机，每次开机时都出现“Ｐｒｅｓｓ＜Ｆ１＞ｔｏＲＥＳＵＭＥ”，按Ｆ１进入ＣＭＯＳ设置状态。故障分析和处理：微机设置的参数一般采用ＣＭＯＳ记忆参数电路，在关机后由充电电池来供电，由于电池...     

SOI／SDB COMS环形振荡器的研究

本文主要研究了硅片直接键合技术制备ＳＯＩ材料，并在此材料上采用全离子注入硅栅工艺制造了１μｍ沟道ＣＭＯＳ环形振荡器。由于ＳＯＩ。ＳＤＢ中的硅膜保持着本体硅的性质，故所得陪管的特性比较好，（迁移率：ＮＭＯＳ为６８０ｃｍ２／Ｖ·ｓ，ＰＭＯＳ为３７０ｃｍ２／Ｖ·ｓ，跨导：ＮＭＯＳ为３８ｍＳ，ＰＭＯＳ为２５ｍＳ）。但发现ＭＯＳ管具有“Ｋｉｎｋ”效应，随着硅膜厚度的减小，“Ｋｉｎｋ”效应有所抑制。实验所得ＣＭＯＳ１９级环形振荡器的单级延时为０．７９ｎｓ，由此可见，ＳＯＩ／ＳＤＢ材料在ＶＬＳＩ中将有很大的发展前景     

用于亚微米CMOS的轻掺杂漏工艺

本文研究了轻掺杂漏工艺对器件特性的影响。优化了轻掺杂区离子注入的剂量和能量。优化的ＳｉＯ２侧墙ＬＤＤ工艺有效地抑制了短沟道效应。研制成功了沟道长度为０．５μｍ的ＣＭＯＳ２７级环振电路，门延迟为１７０ｎｓ．     

Sn Oxide States of SnO_x Films Induced by Vacuum Annealing

ＳｎＯｘｉｄｅＳｔａｔｅｓｏｆＳｎＯｘＦｉｌｍｓＩｎｄｕｃｅｄｂｙＶａｃｕｕｍＡｎｎｅａｌｉｎｇＨ．ＹａｎＧ．Ｈ．ＣｈｅｎＧ．Ｙ．Ｃａｏ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＰｈｙｓｉｃｓ，ＢｅｉｊｉｎｇＰｏｌｙｔｅｃｈｎｉｃＵｎｉｖｅｒｓｉｔｙ...     

惰性气体分子及其二聚物的紫外高分辨激光光谱

惰性气体分子及其二聚物的紫外高分辨激光光谱蔡继业（中国科学院安徽光机所激光光谱室合肥２３００３１）ＤｉｍｏｖＳＳＬｉｐｓｏｎＲＨ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ｔｈｅＵｎｉｖｅｒｓｉｔｙｏｆＷｅｓｔｅｒｎＯｎｔａｒｉｏ，ＬｏｎｄｏｎＯｎ...     

不同CO吸附类型对超细SnO_2气敏元件的作用

本工作采用超细ＳｎＯ２为基体，ＣＯ为检测气体，检测了烧结型ＳｎＯ２元件在不同温度下的气敏效应．同时利用流动饱和法测试了粉体不同温度下对ＣＯ的可逆及不可逆吸附量．一方面通过新材料的使用，降低了元件的工作温度；另一方面，通过吸附测试与气敏效应的关联，认为：超细粉体低温时表面可逆ＣＯ量的存在，是其能够降低工作温度的主要原因．粉体表面的不可逆ＣＯ量直接影响着元件的响应输出（灵敏度）．材料本身的吸附总量和气敏特性有着良好的对应关系．ＳｎＯ２元件气敏效应的发挥是粉体表面可逆与不可逆吸附共同作用的结果．     

SnO2／Si的光伏特性

采用ＣＶＤ方法在硅单晶上制备ＳｎＯ２薄膜，对不同硅衬底及在不同温度下淀积ＳｎＯ２制得ＳｎＯ２／Ｓｉ进行光电压谱的测量，得出最佳的制备温度；采用类金属半导体接触模型，推导出有关计算公式，计算得出其介面复合速度和异质结势垒宽度等参数。     

Fe_2O_3-SnO_2双层薄膜对氨气敏感特性及其机理研究

本文报道了以Ｆｅ（ＣＯ）５和ＳｎＣｌ４为源，采用ＰＥＣＶＤ技术淀积Ｆｅ２Ｏ３－ＳｎＯ２双层薄膜，将该薄膜淀积在陶瓷管上，对氨气的敏感特性进行了测量，并讨论了敏感机理．     

无团聚纳米级SnO_2粉末及其气敏元件的制备

用液相沉淀法在结晶五水四氯化锡的水溶液中滴加浓氨水，通过在沉淀时加入高分子有机分散剂，剧烈搅拌，控制反应结束时ｐＨ值，用无水乙醇洗涤、冷冻干燥及选取适当的煅烧温度等一系列工艺手段来制取ＳｎＯ２粉末。将得到的粉末用ＴＥＭ、ＢＥＴ及ＸＲＤ半峰宽法测定其粒径大小，证明粉末最小平均粒径可至３．７９ｎｍ且无团聚存在，ＸＲＤ分析表明所得的ＳｎＯ２为四方相。将此粉末制成气敏元件，经测试表明气敏性能有很大提高。     

SnO2纳米线的低温生长及光致发光研究

在550℃下,通过Au-Ag合金助催热蒸发氧化亚锡,制备了25nm的Sn02纳米线.测试了Sn02纳米线的室温光致发光谱,其四个发光峰中,418nm的峰足新发现的峰,它是孪晶纳米线的面缺陷造成的.SnO2纳米线的低温生长机制遵从VLS生长机制,且与5nO粉末的应用有一定的关系.Sn02纳米线的较小尺度与气相因子的低温度低浓度化学反应有关.     

Average latency and link utilization analysis of heterogeneous wormhole NoCs

We present a novel methodology for analysis of the average end-to-end latency and link utilization of wormhole NoCs with heterogeneous link capacities and heterogeneous number of virtual channels per unidirectional link. Our analysis methodology supports different heterogeneous NoC topologies for which no analysis framework has been developed in the past. The average end-to-end latency per flow is separated to three components: (1) The time it takes the head-flit to leave the source queue (queuing time at the source); (2) The time it takes the head-flit to reach the destination module (path acquisition time) and (3) The time it takes the rest of the packet to leave the network (transfer time). Furthermore, we take into account the interaction between intersecting flows. The average link utilization is calculated based on the path acquisition time and transfer time. To that end, our analysis introduces a set of implicit equations, which can be efficiently solved iteratively. We demonstrate the accuracy and the efficiency of our approximate analysis by comparing the analysis results to accurate simulations for several synthetic examples and SoC multimedia applications in heterogeneous networks. In addition, we compare the analysis results with HNOCS simulation results for a chip-multi-processor (CMP) using SPLASH-2 and PARSEC traces for both homogeneous and heterogeneous NoC configurations.     

自组装型SnO2纳米线超低浓度H2传感器的研制

采用FESEM及气敏传感器测试系统,研究了用自组装方式制备的SnO2纳米线气敏传感器的氢敏特性。结果表明:在工作温度为200℃时,对于超低浓度[(2~8)×10–6]的氢气具有0.58~1.00的探测灵敏度及3 s的响应时间和10 s的恢复时间。继而从气敏机制、自组装制备方式、SnO2纳米线的优良的比表面特性及其尺度(30~40 nm)低于德拜长度(43 nm)等角度,解释了此传感器对超低浓度氢气具有良好气敏特性的原因。     

Laser-induced desorption of atomic and molecular fragments from a tin dioxide surface modified by a thin organic covering of copper phthalocyanine

The systematic features of laser-induced desorption from an SnO₂ surface exposed to 10-ns pulsed neodymium laser radiation are studied at the photon energy 2.34 eV, in the range of pulse energy densities 1 to 50 mJ/cm². As the threshold pulse energy 28 mJ/cm² is achieved, molecular oxygen O₂ is detected in the desorption mass spectra from the SnO₂ surface; as the threshold pulse energy 42 mJ/cm² is reached, tin Sn, and SnO and (SnO)₂ particle desorption is observed. The laser desorption mass spectra from the SnO₂ surface coated with an organic copper phthalocyanine (CuPc) film 50 nm thick are measured. It is shown that laser irradiation causes the fragmentation of CuPc molecules and the desorption of molecular fragments in the laser pulse energy density range 6 to 10 mJ/cm². Along with the desorption of molecular fragments, a weak desorption signal of the substrate components O₂, Sn, SnO, and (SnO)₂ is observed in the same energy range. Desorption energy thresholds of substrate atomic components from the organic film surface are approximately five times lower than thresholds of their desorption from the atomically clean SnO₂ surface, which indicates the diffusion of atomic components of the SnO₂ substrate to the bulk of the deposited organic film.     

SnO2纳米粉体的制备及其气敏性能研究

以Sn粒为原料,在柠檬酸体系中,用sol-gel法合成了具有四方晶系的SnO2粉体。用XRD、TEM对产物的组成、粒径、形貌进行了表征。结果表明:产物为平均粒径25 nm左右的圆球形颗粒。另外,在最佳工作温度300℃时,采用静态配气法测试了材料的气敏性能,发现SnO2对体积分数为5×10–5的氯气的灵敏度高达805,而且对其它气体有很好的抗干扰能力。元件的响应恢复特性良好,响应时间和恢复时间分别为3 s和7 s。     

MOD法制备SnO2气敏薄膜

本文采用金属有机物热分解(MOD)法制备SnO_2薄膜,探索了锑掺杂对薄膜电阻的调制,通过I—V特性发现Al/SnO_2系统存在零电压电位,最后还测试了薄膜的气敏特性。     

磁控反应溅射SnO2薄膜的气敏特性研究

为研究SnO2薄膜的气敏特性,采用直流磁控反应溅射法制备了SnO2薄膜。探讨和分析了SnO2薄膜气敏元件的敏感机理。对SnO2薄膜的电阻和灵敏度的测试以及对实验结果的分析表明:SnO2薄膜厚度在150~400nm为宜,一般膜厚在250nm时较为敏感。在SnO2薄膜中掺入Pd、Pt、Ag等微量杂质可大大提高SnO2薄膜气敏元件的灵敏度,且使灵敏度的峰值向低温方向移动,增强了对H2、CO和C2H5OH等可燃气体的选择性、响应时间由3min缩短到0.5s以下。     

Revisit of the band gaps of rutile SnO2 and TiO2: a first-principles study

From the recent experimentally observed conduction band offset and previously reported band gaps,one may deduce that the valence band offset between rutile SnO2 and TiO2 is around 1 eV,with TiO2 having a higher valence band maximum.This implication sharply contradicts the fact that the two compounds have the same rutile structure and the Γ3^+ VBM state is mostly an oxygen p state with a small amount of cation d character,thus one would expect that SnO2 and TiO2 should have small valence band offset.If the valence band offset between SnO2 and TiO2 is indeed small,one may question the correctness of the previously reported band gaps of SnO2 and TiO2.In this paper,using first-principles calculations with different levels of computational methods and functionals within the density functional theory,we reinvestigate the long-standing band gap problem for SnO2.Our analysis suggests that the fundamental band gap of SnO2 should be similar to that of TiO2,i.e.,around 3.0 eV.This value is significantly smaller than the previously reported value of about 3.6 eV,which can be attributed as the optical band gap of this material.Similar to what has been found in In2O3,the discrepancy between the fundamental and optical gaps of SnO2 can be ascribed to the inversion symmetry of its crystal structure and the resultant dipole-forbidden transitions between its band edges.Our results are consistent with most of the optical and electrical measurements of the band gaps and band offset between SnO2 and TiO2,thus provide new understanding of the band structure and optical properties of SnO2.Experimental tests of our predictions are called for.