SIMOX材料薄膜厚度的测量和分析

讨论了由国产LC－14型强流氧离子注入机制备的SIMOX（sepqration by implanted oxygen）材料薄膜厚度的测量和分析。采用红外吸收光谱测量SIMOX绝缘埋层的厚度，这是一种快速非破坏性测量方法。根据离子注入原理估算表面硅层的厚度，并分析了影响估算精度的各种因素。     

Mev^28Si^＋注入GaAs的退火行为

报导 MeV 硅离子注入半绝缘 GaAs 的快退火行为,根据缺陷作用原理分析了硅的不均匀激活和载流子分布特征.指出应按载流子浓度、迁移率、埋层电阻和击穿等特性综合评价深埋层和近表面层的品质,优化注入和退火参数.     

杂质纵向高斯分布UTBB-SOI MOSFET的虚拟阴极阈值电压解析模型

采用Sentaurus Process工艺仿真工具,验证了超薄硅膜内单次纵向离子注入并快速热退火后所实现的轻掺杂杂质分布符合高斯规律。设计杂质纵向高斯分布的轻掺杂纳米UTBB-SOI MOSFET,用虚拟阴极处反型载流子浓度来定义阈值电压的方法,为器件建立二维阈值电压解析模型。通过与Sentaurus Device器件仿真结果对比分析,发现:阈值电压模型能准确预测器件在不同掺杂、器件厚度和偏置电压下的阈值电压,正确反映器件的背栅效应,其模拟结果与理论模型相符。     

Surface chemical structure of titania-silica nanocomposite powder

Titania-silica （TS） nanocomposite powder with three different composite structures, containing 10-30 mol% SiO2 in each structure, have been prepared by sol-gel processes. The surface characteristics of these titania-silica samples have been investigated by X-ray photo-emission spectroscopy （XPS） and high resolution transmission electron microscopy （HRTEM）. The study for all TS oxides annealed at 773 and 1173 K showed： an abnormal surface enrichment in Si increased with increasing annealing temperature; the Ti^3＋, Ti^2＋, Si^3＋ and Si^2＋ oxides coexisted with Ti^4＋ and Si^4＋ oxides, and the contents of these Ti/Si suboxides increased with increasing SiO2 content and annealing temperature; there was a layer rich in O on the topmost surface and the excess O could be attributed to the chem-adsorption of H2O; different composite structures could lead to different contents of Ti/Si suboxides. These results indicated that the surface of TS oxide powder derived by sol-gel process was a double layer with enriched O first and then SiOx/TiOy（x, y〈2）. Ti/Si suboxides could result from the thermal diffusion of Ti^4＋ and Si^4＋, which might be induced by the strong interaction between Ti^4＋ and Si^4＋.     

MBE-GaAs/Si的背散射沟道分析

对 MBE-GaAs/Si 进行离子注入和退火.GaAs 外延层的厚度为0.9-2.0μm.Si离子的注入能量及剂量分别为1.2-2.8MeV,l×10~(14)-7×10~(15).cm~(-2).退火采用红外瞬态退火(850℃,15s)及白光退火(1050℃,8s).背散射沟道分析采用4.2MeV~7Li.实验表明,注入结合退火是改善 GaAs 外延层晶体质量的一种有效方法.注入剂量过大,由于正化学配比遭到破坏,外延生长终止.     

Electrocatalytic oxidation of ethanol and ethylene glycol on bimetallic Ni and Ti nanoparticle-modified indium tin oxide electrode in alkaline solution

Bimetallic Ni and Ti nanoparticle-modified indium tin oxide electrode(Ni–TiNPs/ITO) were prepared by a twostep ion implantation method, and their electrocatalytic activity toward the oxidation of ethanol and glycol was evaluated. The ion-implantation method is simple, low-cost and environmental friendly without the use of any binder. The Ni–TiNPs/ITO electrode were characterized by scanning electron microscopy(SEM), atomic force microscopy(AFM) and X-ray photoelectron spectroscopy(XPS). SEM and AFM showed that the nanoparticles on the Ni–TiNPs/ITO electrode had a small range of dispersion(10–20 nm) and high dispersion. Electrochemical performances were measured by cyclic voltammetry(CV) and chronoamperometrics. The Ni–TiNPs/ITO electrode exhibited much higher electrocatalytic activity and stability for ethanol and ethylene glycol oxidation than NiNPs/ITO.     

Si NWs/GQDs复合结构的设计及其光电催化性能

采用金属催化化学蚀刻法制备硅纳米线阵列（silicon nanowire arrays,Si NWs）,通过高速旋涂仪将自上而下法制备的石墨烯量子点（graphene quantum dots, GQDs）负载到Si NWs上。X射线光电子能谱（X-ray photoelectron spectroscopy, XPS）等表征结果证明,GQDs能够通过高速旋涂仪负载到Si NWs上。扫描电子显微镜（scanning electron microscopy, SEM）形貌观测结果表明,蚀刻时间与Si NWs纳米线长度成正比。光电化学测试结果表明,性能最优的蚀刻时间为45 min。与原始硅片相比,GQDs负载的Si NWs光电密度达到了0.95 mA/cm²,性能提升了30多倍。电化学交流阻抗（electrochemical impedance spectroscopy, EIS）测试结果表明：GQDs的加入能显著提升载流子的传输效率。紫外–可见漫反射光谱（ultravioletray-visible diffuse reflectance spectroscopy, UV-Vis DRS）结果显示负载GQDs可以有效提升Si NWs对光的吸收效果。     

埋氧层及铝层对SOI／玻璃静电键合的影响

介绍了SOI／Pyrex玻璃静电键合的实验过程和实验现象,利用电流表对静电键合电流进行测量。发现埋氧层厚度越厚,键合电流越小,键合波扩散速度越小。提高键合电压,能有效增大键合电流及加快键合速度。实验也表明玻璃表面溅射铝层对键合产生较大影响。理论分析了产生这些现象的原因,得出埋氧层厚度和键合电压与静电力的关系式。还提出从阳极引一探针电极到SOI器件层,提高玻璃耗尽层与器件层之间电压,实现厚埋氧层SOI片与玻璃键合的方法。     

Effects of nitrogen ion implantation on lily pollen germination and the distribution of the actin cytoskeleton during pollen germination

The effects of low energy nitrogen ion implantation on lily (Lilium davidii Duch.) pollen germination and the distribution of the actin cytoskeleton during pollen germination have been studied. Preliminary results showed that the ratio of pollen germination increased from (16.0± 1.6)% to (27.0±2.1)% when implanted with nitrogen ions by 100 keV and a dose of 10¹³ ions/cm². Further experiments were performed by staining the actin filaments in pollen with rhodamine-phalloidin and detected by using laser confocol microscopy. After hydration for 10 h, the actin filaments in ion implanted pollen grains tended to form thick bundles oriented in parallel or ring shape at the germinal furrow, indicating that the effect of nitrogen ion implantation on the germination of pollen might be mediated by reorganization of the actin cytoskeleton.     

Direct determination of trace silicon in lanthanum oxide by using a selective volatility and slurry sampling-FETV-ICP-AES

A new method for determination of trace sillicon in high purity lanthanum oxide by using electrothermal vaporization (ETV)-ICP-AES with polytetrafluoroethylene (PTFE) slurry as a fluorinating reagent has been proposed. Under the optimized experimental conditions, the fluorination reactions of analyte (Si) and matrix(La) with PTFE in the graphite furnace took place at high temperature, and the fractional volatilily between Si and La was observed. Based on this principle the matrix interference could be eliminated. The detection limit of Si was 4.0μg·L⁻¹, and the RSD was 3.4%(C=0.2mg·L⁻¹,n=10). The procedure proposed has been applied successfully to determine trace Si in La₂O₃ without any chemical pre-treatment. Supported by the National Natural Science Foundation of China Qin Yongchao: born in Dec. 1953, ph. D., Assciate Professor     

Characterization of ultrathin SiO 2/Si interface grown by low temperature plasma oxidation

Ultrathin SiO 2 layers on Si (100) wafers were prepared by plasma oxidation at a low temperature (250℃). The analyses of X-ray photoelectron spectroscopy (XPS) and TEM reveal that the chemical composition of the oxide layer is stoichiometric SiO 2 and the SiO 2/Si interface is abrupt. The thickness of the ultrathin oxide layer obtained from XPS, capacitance-voltage (C-V) and ellipsometry measurements indicate a nonlinear time dependence. The high frequency C-V characterization of MOS structure shows that the fixed charge density in SiO 2 film is about 10 11 cm -2 . It is also shown that the strength of breakdown electrical field of SiO 2 film with 6 nm thickness is of the order of 10 6 Vcm -1 . These properties of the ultrathin SiO 2 layer ensure its application in silicon quantum devices.     

空间辐射效应防护的标准单元库设计与实现

为提高空间环境下电子设备的可靠性,提升抗辐射加固SOI(Silicon on Insulator)集成电路的设计效率,通过构建完整的建库流程,自主设计开发了基于33 V 035 μm PD（Partly） SOI CMOS(Complementary Metal-Semiconductor)工艺平台,并面向Synopsys电子设计自动化软件的抗辐射加固标准单元库。标准单元采用H型栅及源漏非对称注入结构,以提高抗辐射性能,最后对该单元库进行了电子设计自动化工具流程验证和测试验证。实验结果表明,检错纠错验证电路功能符合设计要求,抗总剂量水平大于300 krad (Si)。     

Silicon dots films deposited by spin-coating as a generated carrier addition layer of third generation photovoltaics

In this work, silicon ink composing of silicon powder and zinc oxide solution was formulated and spin-coated on quartz and n/p-Si substrates followed by drying the films under atmosphere at the temperature of 550°C. The results showed that this top-addition layer could be the highly promising layer for photo-generating carriers in third-generation photovoltaics to enhance blue-light absorption. X-ray diffraction and scanning electron microscopy techniques were used to study the presence of silicon and zinc oxide nano-crystallites. The thin films consisting of different energy bandgap of Si nanocrystals(～100 nm) with narrow bandgap and spherical Zn O:Bi nanocrystal(～20 nm) with wider bandgap could be obtained from the evidence of bandgap enlargement. The band gaps of the thin films were tunable by adjusting silicon dots density in Zn O:Bi film. Energy upshift of light absorption edge depended on the silicon dots density was observed in the range 1.6–3.3 eV related band gap enlargement by Tauc plot. Under illumination, a high photocurrent gain of the thin film comprised of low Si dots density coated on a quartz substrate was about 10~3 times higher compared with its dark current. This result is agreeably explained in terms of its lower superficial trap states at the interface between silicon and zinc oxide matrix. The composite layer can be applied to a third-generation solar cell with the efficiency 1.50% higher than that with a typical crystalline-Si solar cell.     

Electronic transport in nanometre-scale silicon-on-insulator membranes

The widely used 'silicon-on-insulator' (SOI) system consists of a layer of single-crystalline silicon supported on a silicon dioxide substrate. When this silicon layer (the template layer) is very thin, the assumption that an effectively infinite number of atoms contributes to its physical properties no longer applies, and new electronic, mechanical and thermodynamic phenomena arise, distinct from those of bulk silicon. The development of unusual electronic properties with decreasing layer thickness is particularly important for silicon microelectronic devices, in which (001)-oriented SOI is often used. Here we show--using scanning tunnelling microscopy, electronic transport measurements, and theory--that electronic conduction in thin SOI(001) is determined not by bulk dopants but by the interaction of surface or interface electronic energy levels with the 'bulk' band structure of the thin silicon template layer. This interaction enables high-mobility carrier conduction in nanometre-scale SOI; conduction in even the thinnest membranes or layers of Si(001) is therefore possible, independent of any considerations of bulk doping, provided that the proper surface or interface states are available to enable the thermal excitation of 'bulk' carriers in the silicon layer.     

N2O氮化LPCVD氧化物可靠性的改进

通过与热生长氧化物进行比较 ,对LPCVD氧化物及N2 O氮化LPCVD氧化物的质量和可靠性进行了高场应力实验研究 .发现LPCVD氧化物有比热氧化物低的界面态密度Ditm 及小的应力感应Ditm 的增加 ,但电子陷阱产生和俘获率却表现出增强的性能 ,从而使击穿特性退化 .在N2 O氮化后 ,LPCVD氧化物的Si/SiO2界面和体质量得到很大提高 ,其机理在于N2 O氮化导致界面氮的结合及LPCVD氧化物中H2 副产物的有效排除 .     

Effects of high temperature annealing on the dislocation density and electrical properties of upgraded metallurgical grade multicrystalline silicon

High temperature annealing was performed on upgraded metallurgical grade multicrystalline silicon (UMG multi-Si) wafers with a purity of 99.999%. The samples were mechanically polished and chemically etched, and then the microstructures were observed by a scanning electron microscope (SEM). The minority carrier lifetime and resistivity of the samples were measured using microwave photoconductance decay and four-point probe techniques, respectively. The results show that the electrical properties of the samples decrease rather than increase as the annealing temperature increases, while the number of dislocations in bulk Si reduced or even disappeared after annealing for 6 hours at 1100–1400°C. It is considered that the structural microdefects induced by the high concentration of metal impurities (including interstitial or substitutional impurities and nanoscale precipitates) determine the minority carrier recombination activity and thus the electrical properties of UMG multi-Si wafers rather than dislocations in bulk Si.     

LC-14型强流氧注入机注入均匀性的背散射分析报告

报道了应用双指数函数对大注量氧注入硅的背散射谱进行拟合,成功地分离出注入的氧峰.数据处理结果表明,氧注量的均匀性以标准偏差表示为7.8%,基本上达到了设计要求.计算了注氧层和表面硅层的厚度,并且还对注量进行了校正.     

Si含量对TiAlSiN纳米复合涂层的微观结构和力学性能的影响

采用不同Si含量的TiAlSi复合靶,在Si基底片上用射频磁控溅射工艺沉积了TiAlSiN纳米复合涂层,采用X射线衍射仪（XRD）、高分辨透射电子显微镜（HRTEM）和纳米压痕技术研究了Si含量对TiAlSiN涂层的微观结构和力学性能的影响.结果表明：TiAlSiN涂层内部形成了Si₃N₄界面相包裹TiAlN纳米等轴晶粒的纳米复合结构.随着Si含量的增加,TiAlSiN涂层的结晶程度先增加后降低,涂层内部的晶粒尺寸先减小后趋于平稳,涂层的力学性能先升高后降低.当Si与TiAl原子比为3：22时获得的最高硬度和弹性模量分别为37.1 GPa和357.3 GPa.     

Fabrication of TiO2 nanoparticles/nanorod composite arrays via a two-step method for efficient dye-sensitized solar cells

Ti O2nanoparticles/nanorod composite arrays were prepared on the F-doped tin oxide(FTO)substrate through a two-step method of hydrothermal and d.c.magnetron sputtering.The microstructure and optical properties of the samples were characterized respectively by means of X-ray diffraction(XRD),field-emission scanning electron microscopy(FESEM)and UV–vis spectrometer.The results showed that the Ti O2composite nanorod arrays possess the nature of high surface area for more dye molecule absorption and the strong light scattering effects.The dye sensitized solar cells(DSSCs)based on Ti O2composite nanorod arrays exhibited a 80%improvement in the overall energy conversion efficiency compared with the pure Ti O2nanorod arrays photoanode.     

基于有效介电函数的SOI材料的光学表征

通过参考有关文献关于卢瑟福背向散射能谱(rutherford back scattering spectrometry,RBS)、透射电镜(transmission electron microscope,TEM)、俄歇电子能谱(auger electron spectroscopy,AES)、红外反射谱法(infra...