图像的小波可变阈值去噪方法

鉴于当前智能手机显示屏多采用RGBG格式的像 素结构,本文提出了应用于AMOLED的RGB到 RGBG高速像素转换技术(HSHQ)。该技术的特征是先区分出简单转换点和复杂转换点,对于 简单转换点采 用直接赋值实现像素转换,对于复杂转换点,采用权重因子算法实现像素转换。本文主要有 三个创新点:(1) 不同于传统方法对图像中所有像素进行复杂转换,本文首创性地提出了以相邻像素单 元的灰阶差值作 为判断依据,进行转换像素标记,区分出简单转换点和复杂转换点,只针对标记点进行复杂 像素结构转换。 因此,该方法提高了像素转换速度。(2) 对于简单转换点,采用直接赋值法,由于原图像 的灰阶不做改变, 该方法完全保留了简单转换点的图像信息。(3) 对于复杂转换点,采用权重因子算法,在 将转换前后信息损失降至最低的同时,抑制了彩边效应。 相比于DA算法,HSHQ算法处理所得图像的PSNRU和PSNRV分别提高了7.04%和6.62%。相比于ED MSE,HSHQ算法的转换率降低了75.63%。因此,本文提出的算法在保证转换质量的同时,大 大提高了转换速度。     

基于PEN柔性衬底的顶发射微腔OLED性能研究

设计了结构为Ag/MoOx空穴注入层(HIL)/有机层/LiF/Al/Ag/Alq3的柔性有机电致发光器件(FOLED),研究通过改变HIL层的厚度改变腔长实现对微腔效应的调节,制备了性能优化的微腔FOLED。通过器件性能的对比,得到了可用Ag作为反射阳极的顶发射微腔FOLED全彩显示器件优化结构,即蓝、绿和红FOLED对应的优化HIL层厚度分别为100nm、120nm和160nm。     

基于光学三角形法的太阳帆板平面度测量系统

介绍了一种采用斜光学三角形测量结构和基于虚拟精密测量基准的太阳帆板平面度无接触测量系统及其误差补偿方法。提出的虚拟精密基准的建模与误差补偿技术 ,解决了在非精密基准上实现精密测量的问题 ,研制的系统利用现有平台可实现对太阳帆板平面度的高精度测量。测量结果表明 ,系统对面积为 2 5 81mm× 175 5mm太阳帆板的平面度测量精度达 0 .0 2mm(rms)。     

基片温度对电子束蒸发的ZnS薄膜性能的影响

采用电子束蒸发在不同基片温度下沉积ZnS薄膜,研究了基片温度对薄膜性能的影响.结果表明:不同基片温度下沉积的ZnS薄膜均呈多晶状态,为体心立方(闪锌矿)结构的β-znS,并具有明显的(111)面择优取向,导电类型为n型.随着成膜时基片温度的提高,薄膜结晶度越来越好,透过率增大,载流子浓度增大,而电阻率减小.     

Ordered InAs nanodots formed on the patterned GaAs substrate by molecular beam epitaxy

Ordered indium arsenide (InAs) nanodots are formed by molecular beam epitaxy (MBE) on patterned gallium arsenide (GaAs) substrates, which are prepared by implanting manganese (Mn) ions through anodic aluminum oxide (AAO) membranes into the GaAs wafers. Morphology and structure of the patterned GaAs substrate is determined both by the oxygen desorption and the Mn ion diffusion. Suitable patterned GaAs substrates with the same dosage of Mn ions for the following epitaxy can be obtained by controlling the deoxidization As₄ pressures during the oxygen desorption. Images of samples with different Mn ion implantation dosages and different molecular beam epitaxial conditions for the following deposition of InAs nanodots on the patterned GaAs substrates are characterized by atomic force microscopy (AFM). The order of the InAs nanodots is determined both by the AAO membrane and dosage of Mn ions. The density of InAs nanodots has great relation to the pore density of the AAO.     

The effects of substrate bias,substrate temperature,and pulse frequency on the microstructures of chromium nitride coatings deposited by pulsed direct current reactive magnetron sputtering

Recently, great attention has been devoted to the pulsed direct current (DC) reactive magnetron sputtering technique, due to its ability to reduce arcing and target poisoning, and its capability of producing insulating thin films. In this study, chromium nitride (CrN) coatings were deposited by the bipolar symmetric pulsed DC magnetron reactive sputtering process at different pulse frequency, substrate bias voltage, and the substrate temperature. It was observed that the texture of CrN changed from (111) to (200) as substrate temperature increased to 300°C as deposited at 2 kHz without substrate bias. With increasing pulsing bias and pulse frequency of target, predominated (200) orientation of CrN film was shown due to the ion bombardment/channeling effect to preferentially sputter those unaligned planes. For the CrN coatings deposited with pulsed biasing, the grain size decreased with increasing pulse frequency and substrate bias, whereas the surface roughness showed a reverse trend. The deposition rate of the CrN films decreased with increasing pulse frequency. It was concluded that the pulse frequency, substrate bias, and substrate temperature played important role in the texture, microstructure, and surface roughness of the CrN coatings deposited by the pulsed DC magnetron sputtering process.     

激光微细熔覆电阻浆料直写电阻技术初步研究

应用一种新工艺——激光微细熔覆电阻浆料直写电阻技术,在陶瓷基板上制备厚膜电阻。介绍了新工艺研究的初步成果,及激光直写的附着机理,并展示了部分线电阻及通过搭接获得的电阻图案。重点讨论工艺参数的影响,研究了预置膜层厚度、激光功率和激光扫描速度对电阻线宽的影响规律。     

Signal noise perturbation on automotive mixed-mode semiconductor device generated by graded substrate defect

The semiconductor technologies evolution allows greatly reducing noise impact on products and many structures have been created to reduce its effect. However, this paper presents the apparition of a noise issue during the production of a mixed-mode device dedicated to automotive applications. The research investigations concerned the fact that failure was not detected at test level but at customer level; therefore, it was determinant to understand the root cause of this failure mode to drive corrective actions in order to secure customer. The challenge was to analyse noise in Failure Analysis (FA) without fault spatial localization results. Indeed, Light Emission Microscopy (EMMI) and Thermal Laser Stimulation (ex: Soft Defect Localization – SDL) were unable to provide any defective area in the product. The lack of failing device identification led us to combine electrical and design analyses in order to define hypothesis on the failure origin. It was then possible to drive physical investigations through different approaches, using physical cross-section, Secondary Ion Mass Spectrometry (SIMS) and Scanning Capacitance Microscopy (SCM) techniques. Finally, the obtained complementary results will be discussed and an explanation of the failure mechanism will be presented as the root cause issue, allowing defining the defective step in production process.     

激光离散预处理镀铬身管的基体烧蚀行为研究

为了揭示激光离散预处理基体提高某种型号镀铬身管寿命的机理,采用实验方法,对激光离散处理和未处理的寿终镀铬身管基体烧蚀行为进行了定量对比分析,发现经激光离散处理的没有明显烧蚀沟,并且其基体的烧蚀量比激光未处理的降低了10%。结果表明,降低的原因是受激光处理控制的间距较大的铬层主裂纹扩展到了烧蚀层,增加了影响烧蚀层剥落的主裂纹间距,延缓了烧蚀层的剥落时间。这一结果对进一步分析激光离散预处理基体提高镀铬身管寿命是有帮助的。     

Influence of substrate on high-temperature behavior of copper film studied in situ by electron backscatter diffraction

Change in the in-plane orientation of (111) grains in the copper film was studied in situ by electron backscatter diffraction (EBSD) during its thermal treatment inside the scanning electron microscope (SEM). Two separate investigations were carried out each at different locations of the film. Both of the investigations showed the presence of (111) fiber texture with increased strengths of {111}〈112〉 and {111}〈110〉 orientations. During the first investigation, the {111}〈110〉 component became sharper relative to {111}〈112〉, while in the second investigation the sharpness decreased relative to {111} 〈112〉 with increasing temperature. No such changes in the in-plane orientation of the (111) grains were observed during the similar experiment carried out on the Cu film in freestanding condition. The role of silicon subtrate on influencing these changes has been proposed based on dislocation activity within the grains. The increase in the inclination of (111) planes to the specimen surface in {111}〈110〉 and {111}〈112〉 grains as a function of temperature was linked to the stress relaxation. The inclination of the (111) planes to the specimen surface leads to decrease in the sharpness of the (111) texture components. Finally, similar transformation in the texture of (111) grains in Cu damascene interconnects was investigated.     

生长温度对于Ge衬底上分子束外延生长的InGaAs/GaAs量子阱结构质量的影响

本文研究了斜切割（100）Ge衬底上InxGa1-xAs/GaAs量子阱结构的分子束外延生长（In组分为0.17或者0.3）。所生长的样品用原子力显微镜、光致发光光谱和高分辨率透射电子显微镜进行了测量和表征。结果发现,为了生长没有反相畴的GaAs缓冲层,必须对Ge衬底进行高温退火。在GaAs外延层和InxGa1-xAs/GaAs量子阱结构的生长过程中,生长温度是一个至关重要的参数。文中讨论了温度对于外延材料质量的影响机理。通过优化生长温度,Ge衬底上的InxGa1-xAs/GaAs量子阱结构的光致发光谱具有很高的强度、很窄的线宽,样品的表面光滑平整。这些研究表面Ge 衬底上的III-V族化合物半导体材料有很大的器件应用前景。     

衬底温度对PLD法制备的ZnO:Ga薄膜结构和性能的影响

利用脉冲激光沉积法在石英衬底上制备了镓掺杂氧化锌(ZnO:Ga)透明导电薄膜,研究了衬底温度对薄膜的结构、表面形貌和光电性能的影响.研究表明:制备的ZnO:Ga薄膜是具有六角纤锌矿结构的多晶薄膜.随着衬底温度的增加,衍射峰明显增强,晶粒尺寸增大.当衬底温度为450℃时,薄膜的最低电阻率为8.5×10<'-4>Ω·cm,...     

Influence of growth temperatures on the quality of InGaAs/GaAs quantum well structure grown on Ge substrate by molecular beam epitaxy

Molecular beam epitaxy growth of an In_xGa_1-xAs/GaAs quantum well（QW） structure（x equals to 0.17 or 0.3） on offcut（100） Ge substrate has been investigated.The samples were characterized by atomic force microscopy,photoluminescence（PL）,and high resolution transmission electron microscopy.High temperature annealing of the Ge substrate is necessary to grow GaAs buffer layer without anti-phase domains.During the subsequent growth of the GaAs buffer layer and an In_xGa_1-xAs/GaAs QW structure,temperature plays a key role. The mechanism by which temperature influences the material quality is discussed.High quality In_xGa_1-x As/GaAs QW structure samples on Ge substrate with high PL intensity,narrow PL linewidth and flat surface morphology have been achieved by optimizing growth temperatures.Our results show promising device applications forⅢ-Ⅴcompound semiconductor materials grown on Ge substrates.     

衬底温度对电子束沉积LaF3薄膜性能的影响

采用电子束沉积的方法分别在K9玻璃、紫外熔凝石英和Si基片上制备了LaF3单层膜,研究了衬底温度对LaF3薄膜结构和光学性能的影响.衬底温度从200℃上升到350℃,间隔为50℃,用分光光度计测量样品的透射率光谱曲线,并进行光学常数的计算.利用原子力显微镜(AFM)进行表面粗糙度的标定,利用ZYGO干涉仪测量基板镀膜前...     

Optical and structural properties of CuCrO2 thin films on c-face sapphire substrate deposited by reactive RF magnetron sputtering

Reactive sputtering with Ar/N₂ mixture gas was introduced to improve stoichiometry of p-type transparent CuCrO₂ films, and effects of N₂ partial pressure ratio (α_N) on optical and structural properties were investigated. Film composition was changed from Cu rich (i.e. Cr poor) to Cr rich (i.e. Cu poor) by N₂ addition, and the stoichiometric film was grown at α_N of about 20%. Although N atoms were not incorporated into the films from analyses of crystal structure and chemical bonding state, both transmittance from visible to near-infrared wavelength and crystallinity were improved at α_N up to 10%. These improvements were attributed to suppression of the CuO formation and promotion of the O-Cu-O dumbbell bonds formation. This was confirmed by the decrease of diffraction intensity from CuO and the increase of vibrational intensity corresponding A_1g mode. From these results, it can be considered that N atoms decreased not only Cu but also excess O in the film. At α_N of 20% or above, transmittance at wavelength of 450 nm and crystallinity deteriorated. This is supposed that excessive N₂ addition probably generated both O and Cu deficiencies. As a result, it was found that slightly Cu-rich composition is suitable to obtain high-transparency CuCrO₂ thin films for practical use.     

Indium Tin Oxide Thin Films Grown on Polyethersulphone (PES) Substrates by Pulsed‐Laser Deposition for Use in Organic Light‐Emitting Diodes

High quality indium tin oxide (ITO) thin films were grown by pulse laser deposition (PLD) on flexible polyethersulphone (PES) substrates. The electrical, optical, and surface morphological properties of these films were examined as a function of substrate temperature and oxygen pressure. ITO thin films, deposited by PLD on a PES substrate at room temperature and an oxygen pressure of 15 mTorr, have a low electrical resistivity of 2.9×10^?4 Ω cm and a high optical transmittance of 84 % in the visible range. They were used as the anode in organic light‐emitting diodes (OLEDs). The maximum electro luminescence (EL) and current density at 100 cd/m² were 2500 cd/m² and 2 mA/cm², respectively, and the external quantum efficiency of the OLEDs was found to be 2.0 %.     

沉积速率对硅基LiNbO3光波导薄膜特性的影响

利用脉冲激光沉积技术(PLD)在硅衬底上生长高c轴取向LiNbO3晶体薄膜,研究了激光脉冲频率即薄膜沉积速率对薄膜结晶质量及取向性的影响,发现激光脉冲频率对薄膜的c轴取向性基本没有影响,但对薄膜的结品质量影响较大,激光脉冲频率为3 Hz时获得了高结品质量的c轴取向LiNbO3晶体薄膜.XPS测试表明制得薄膜的组分符合等化学计量比,AFM测试显示制备的薄膜表面光滑,表面粗糙度为4.3 nm.棱镜耦合法测试表明制备的LiNbO3薄膜具有优异的光波导性能,光传输损耗为1.14 dB/cm.     

Flexible Cu(In,Ga)Se2 solar cell on stainless steel substrate deposited by multi‐layer precursor method: its photovoltaic performance and deep‐level defects

Cu(In,Ga)Se₂ (CIGS) films on soda‐lime glass and stainless steel (SUS) substrates with several [Ga]/([Ga] + [In]), GGI, and Fe concentrations are fabricated by so‐called “multi‐layer precursor method”. From optical deep‐level transient spectroscopy, deep‐level defect located at 0.8 eV from valence band maximum (E_V) is observed. This defect becomes recombination center when GGI is over 0.4, thereby decreasing cell performances. Fe‐related deep‐level defect is moreover detected in CIGS film on SUS substrate situated at 0.45 eV from E_V. Its density is consistent with Fe concentration in CIGS films. According to SCAPS simulation and experimental results, Fe concentration of above threshold (1.0 × 10¹⁶ atom/cm³) decreases carrier lifetime and carrier density and has more harmful influence on cell performances with GGI of above 0.4. On the other hand, Fe concentration of below threshold (1.0 × 10¹⁶ atom/cm³) has no detrimental impact on cell performances. Namely, conversion efficiency (η) is slightly changed by below 2%. CIGS solar cell on SUS substrate with η of 17.5% is fabricated by decreasing Fe concentration to approximately 5.2 × 10¹⁶ atom/cm³ although higher than the threshold value. Copyright © 2016 John Wiley & Sons, Ltd.