Crystal growth induced by Nd:YAG laser irradiation in patterning glass ceramic substrates with dots

In this work a glass ceramic substrate was processed by focusing a laser beam inside the said material. The crystal phase within the amorphous matrix provides mechanical properties to the glass ceramic substrate in such a way that dots can be patterned inside the fore-mentioned material without producing any cracks. These marks are made up of crystals, the growth of which has been induced by the laser beam. These inner structures can modify the optical, thermal and mechanical properties of the glass ceramic substrate.A Q-switched Nd:YAG laser at its fundamental wavelength of 1064 nm with pulsewidths in the nanosecond range has been used.Morphology, composition, microstructure, mechanical and thermal properties of the processed material are described.     

Scratching by pad asperities in chemical-mechanical polishing

In the fabrication of micro- and nano-scale semiconductor devices and electromechanical systems, the chemical-mechanical polishing (CMP) process is extensively employed. During the CMP process, undesirable scratches are produced on metal-interconnect and low-k-dielectric surfaces by the softer pad asperities. This paper presents contact mechanics models for the initiation of scratching in terms of the pad asperity geometry, the interfacial friction, and the mechanical properties of materials. Results of dry, wet and lubricated experiments on Cu coatings qualitatively validate the theoretical models. To mitigate scratching by pad asperities during CMP, the developed models suggest that the friction coefficient be kept below 0.2.     

Holography and plasma oxidation for uniform nanoscale two dimensional channel formation of vertical organic field-effect transistors with suppressed gate leakage current

Vertical organic field-effect transistors (VOFETs) with nanoscale channel openings have been fabricated using pentacene as an active layer material. To achieve uniform nanoscale two-dimensional channel openings, a laser holography lithography has been introduced. Uniformly distributed and well-aligned holes with 250 nm diameter were successfully obtained with the laser holography lithography. VOFET devices with these channel openings have shown high on/off ratio of about 10³ without any further treatment. Gate leakage current was also decreased with an additional insulating layer generated on the gate electrode sidewall via plasma oxidation.     

基于SEMI标准的集成电路制造装备控制系统设计

随着集成电路制造装备的复杂度越来越高,设计一个符合SEMI标准的集成电路制造装置控制系统显得尤为重要。针对SEMI标准的要求,提出了一种控制系统的结构设计方法。设计的系统定义了SEMI标准中规定的控制模型与状态模型及其他操作,能够满足实际控制需要与SEMI标准的要求。     

鼻内镜下CO2激光辅助手术治疗儿童上颌窦后鼻孔息肉15例

目的:提高上颌窦后鼻孔息肉的手术疗效,降低复发率。方法:回顾性分析2000年6月-2002年1月期间于上海交通大学附属第六人民医院耳鼻咽喉科收治的鼻内镜下CO2激光辅助手术治疗的上颌窦后鼻孔息肉的患者15例,9例为复发的再次手术病例。结果:所有患者随访6-38月(平均23个月)没有发现上颌窦后鼻孔息肉的复发、1例术后鼻腔粘连。结论:该术式可以彻底清除上颌窦后鼻孔息肉,防止复发提高手术疗效。     

基于激光的散斑干涉术及其测量中的应用

对电子散斑干涉技术用于测试离面和面内位移的原理和光路进行了详细阐述,并分析该方法的适用范围和灵敏度,给出了圆盘试件离面位移和金瓷试件面内位移的测试结果。表明基于激光技术的电子散斑干涉法适用于硬质材料位移和无损检测,结果以干涉条纹图形式给出,易于定性和定量分析研究对象位移。     

粉末材料性能对SLM模型制造过程影响的研究

区域选择激光熔化(SLM)技术是金属模型和零件直接制造方法之一。采用相同激光参数加工不锈钢、工具钢、钛合金、铝合金等金属粉末时,铝合金粉末发生成球结晶现象,而其他金属粉末则形成致密的冶金结合。在模型加工过程中,铝合金粉末表现出铺粉性能差,制成的模型表面质量差等现象。由于不同的金属粉末具有不同的对激光的吸收能力、热传导、比热容、比重等性能,造成了上述加工过程和加工质量的不同。文章分析了具体原因,并采用简化的有限元计算证明了不同材料的热物理性能对这一激光加工过程的影响。     

光无线局域网上行链路中的光束对准设计

光链路是无线局域网安全性的物理层解决方案,其中上行链路为便携式终端设备设计的LD发射光束对准是关键问题之一。在Windows平台上展示了一种自动对准的软硬件控制方法,利用Windows中的Direct Show函数库,对激光光斑与目标的对准情况进行视频信号采集和图像识别,为简化识别算法,以蓝色为特征颜色并以一个特定的形状来标识对准目标,以650 nm红色LD为识别导向光束。使之位于红外传输光束中心位置左右,通过识别LD红色光斑与蓝色目标并判断它们之间偏差的方位和距离,将数据输出到下位机控制的微型云台,在二维方位上校准光斑与目标的偏差,同时通过红外LD实现了发送端到接收目标的光信号传输。     

Growth of highly (1 1 1) oriented CuIn0.75Al0.25Se2 thin films

CuIn_0.75Al_0.25Se₂ thin films prepared onto glass substrates at T_S=573 K were single phase, nearly stoichiometric and polycrystalline with a strong (1 1 1) preferred orientation showing sphalerite structure. The results of X-ray diffraction and electron diffraction studies are compared, interpreted and correlated with micro-Raman spectra. The optical absorption studies indicated a direct band gap of 1.16 eV with high absorption coefficient (>10⁴ cm^?1) near the fundamental absorption edge.     

小波域中值滤波在激光陀螺信号处理中的应用

各种随机噪声是导致激光陀螺产生误差的主要因素,且其性质特殊,很难用传统的滤波方法去除。为了减小激光陀螺的随机误差,提高测量精度,提出了小波域的中值滤波器滤波方法,对激光陀螺零漂数据进行了滤波,并采用Allan方差法对滤波效果进行了定量分析。结果表明,此方法的滤波效果优于中值滤波和小波软阈值滤波效果,能有效地减小激光陀螺零漂信号中的角度随机游走、角速度随机游走、速率斜坡、零偏不稳定性和量化噪声,提高激光陀螺零漂输出的稳定性。