Effect of Ta addition on magnetic properties of (Fe45Pt55)1−x-Tax thin films

It was studied that FePt-Ta thin films prepared on MgO (1 0 0) buffer-layer by DC/RF magnetron co-sputtering have shown better magnetic properties and micro structural improvement. The Ta-doped FePt-Ta films indicate somewhat differences in micro structural ordering and the aspect of grain growth after annealing. With respect to magnetic property, the sample having 30% increased coercivity was obtained after a heat treatment at 700 °C. In particular the addition of Ta (5.5%) enhances the L1₀ ordering of FePt at relatively high temperature (above 500 °C).     

玻璃基板激光选区镀膜研究

针对传统制备导电薄膜工艺复杂、成本高,且在激光直写导电膜中存在所加入的辅料造成杂质污染以及膜的厚度和粗糙度难以降低等问题,本文采用玻璃衬底激光制备Zn/Al混合粉末生成导电薄膜,实现了无粘结剂和辅料的薄膜生成,研究了工艺参数调节对膜的生成质量的影响。结果表明,过低或过高的激光扫描速度都会使表面粗糙度增加,扫描速度过慢时...     

Modeling growth rate of HfO2 thin films grown by metal-organic molecular beam epitaxy

HfO₂ dielectric layers were grown on the p-type Si (100) substrate by metal-organic molecular beam epitaxy (MOMBE). Hafnium-tetra-butoxide, Hf(O·t-C₄H₉)₄ was used as a Hf precursor and Argon gas was used as a carrier gas. The thickness of the HfO₂ film and intermediate SiO₂ layer were measured by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The properties of the HfO₂ layers were evaluated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high frequency (HF) capacitance-voltage (C-V) measurement, and current-voltage (I-V) measurement. C-V and I-V measurements have shown that HfO₂ layer grown by MOMBE has a high dielectric constant (k) of 20-22 and a low-level of leakage current density. The growth rate is affected by various process variables such as substrate temperature, bubbler temperature, Ar and O₂ gas flows and growth time. Since the ratio of O₂ and Ar gas flows are closely correlated, the effect of variations in O₂/Ar flow ratio on growth rate is also investigated using statistical modeling methodology.     

Inkjet printed silver source/drain electrodes for low-cost polymer thin film transistors

Silver tracks for source/drain (S/D) electrodes in low-cost polymer thin film transistors (TFTs) have been realized through inkjet printing technique, using heavily n-doped silicon wafer with thermally grown silicon dioxide as the substrate and poly(3-hexylthiophene) (P3HT) as the channel material. Spin coating a layer of poly-4-vinylphenol (PVPh) onto the substrate was found to enhance the silver track uniformity and lower the cure temperature (from 300 to 210 °C). The surface roughness of the PVPh film was optimized to improve the device performance. The fabricated P3HT TFT with a channel length of 20 μm exhibited a saturation mobility of 3.5 × 10⁻2 cm²/V/s which was three times higher than that obtained in P3HT TFTs with gold S/D electrodes.     

电磁屏蔽膜设备的开发及应用

介绍了国内外对电磁屏蔽膜(EMI)研究的现状,比较了制备EMI膜的各种方法,指出采用磁控溅射法制备的EMI膜质量较好,并给出制备EMI膜的工艺流程。     

用于器件描述和电路仿真的新型多晶硅TFT直流模型

提出一种新型的多晶硅薄膜晶体管电流-电压物理模型.考虑了陷阱态密度的V形指数分布,运用Lambert W函数推出了表面势的显式求解方法,大大提高了运算效率,在电路仿真中发挥了重要作用.基于指数的陷阱态密度和计算的表面势,描述了亚阈值区和强反型区的漏电流特性.推导了完整、统一的漏电流表达式,包括翘曲效应.在很广的沟道长度范围和工作区内,模型和实验数据一致.     

Photo-assisted metal-organic chemical vapor deposition of CaCu3Ti4O12 (CCTO) thin films

Calcium copper titanate (CaCu₃Ti₄O₁₂) or CCTO is one of the most researched giant dielectric constant materials in recent years. In the present work, incoherent light source based photo-assisted metal-organic chemical vapor deposition (MOCVD) has been used to prepare CCTO thin films on Si/SiO₂ substrates. Key to this unique processing technique is the use of UV radiation as an additional source of energy in conjunction to the thermal energy. The given Photo-assisted MOCVD processing resulted in polycrystalline CCTO growth on a SiO₂ surface. Powder X-ray diffraction and scanning electron microscopy were performed to analyze structural and compositional properties of the CCTO thin film. Ellipsometric measurements indicated a refractive index of 3.03 for the CCTO thin film.     

不同衬底材料对光刻胶剖面的影响

文章研究了在127mm硅片上分别生长金属铝和二氧化硅氮化硅叠两种IC常用材料作为衬底对光刻胶形貌的影响,其造成光刻胶形貌差的原因是金属底部反射率高导致光刻胶侧面曝光和入射光通过二氧化硅氮化硅叠层厚度的光程差正好为光源波长的整数倍,从而导致光刻胶底部干涉光同相位。通过增加底部抗反射层和调整最佳膜层厚度解决了在这两种衬底材料下光刻胶形貌差的问题。     

基于相控阵雷达的群目标准自适应调度策略研究

群目标是指空间间距、运动方向与速度基本一致的多目标集合,该集合内的目标具有平均电影特性。对这种特殊目标群的跟踪算法研究已经较为深入,但其调度策略研究尚存在很大欠缺。为此,根据相控阵雷达资源调度灵活的特点,针对群目标调度策略尚存在欠缺的问题,在分析了传统相控阵雷达调度策略的基础上,剖析了群目标的特性,提炼了群目标跟踪调度策略的要素。在此基础上,提出了相控阵雷达群目标跟踪准自适应调度策略,并进行了仿真分析。仿真结果表明,所提出的准自适应调度策略能够有效地提高相控阵雷达的跟踪能力。     

CoFe_2O_4薄膜厚度对其微结构和磁性能的影响

以铁和钴的硝酸盐为主要原料,采用sol-gel旋涂法在Si(001)基片上制备了不同厚度的CoFe2O4(CFO)薄膜。研究了薄膜厚度对其结构、形貌及磁性能的影响。结果表明:随着其厚度的增大,薄膜的结晶度变好,薄膜晶粒度逐渐增大到70nm。Ms随着薄膜厚度的增大先增大后减小;Hc的变化规律和Ms相反。当薄膜厚度为800nm时,Ms达到最大值59.2A·m2/kg,此时Hc最小为106.7kA/m。该薄膜具有高度的平行各向异性。