Surface modification of silicon by laser surface treatment: Improvement of adhesion and copper deposition

We have studied the use of lasers for modifying the surface properties of silicon to improve its wettability and adhesion characteristics. Using a 4th harmonic Nd:YAG (λ = 266 nm, pulse) laser, the wettability and adhesion characteristics of the silicon surfaces have been enhanced by laser irradiation. It was found that laser surface treatment of silicon modified the surface energy. By the contact angle measurement, using distilled water, the wetting characteristics of silicon after the laser irradiation show a decrease in the contact angle and a change in the surface chemical composition. In the case of the laser-treated silicon surface, laser direct writing of copper lines has been achieved through pyrolytic decomposition of copper formate by using a focused Ar⁺ laser beam (λ = 514.5 nm, continuous wave (CW)) on the silicon substrates. The deposited lines and surface chemical compositions were measured by energy dispersive x-ray (EDX), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and surface profiler (Alpha Step 500, San Jose, CA) to examine the cross section of deposited copper lines.     

Non-destructive Raman evaluation of a heavily doped surface layer fabricated by laser doping with B-doped Si nanoparticles

The heavy B-doping of an intrinsic Si(1 0 0) wafer has been performed by irradiating a B-doped Si nanoparticle film on the surface of the Si(1 0 0) substrate with energy densities of 8.0 and 16.0 J/cm² by 532-nm laser light. The thicknesses of the heavily doped surface layers were investigated using Raman spectroscopy. The observed 488.0-nm-excited Raman bands were decomposed into two bands: a Fano-type band due to the heavily doped Si surface layer and a Voigt band due to the lightly doped, intrinsic Si region. The analysis of the Fano-type band indicated that the carrier concentration of the heavily doped region was larger than approximately 10¹⁹ cm⁻³. Based on the two-state model, the thicknesses of the heavily doped surface layers were 480 and 630 nm for the samples prepared with energy densities of 8.0 and 16.0 J/cm², respectively. These values were consistent with those obtained by secondary ion mass spectroscopy (SIMS).     

原子层沉积薄膜之激光损伤性能分析

采用目前尚在国内鲜有报道的原子层沉积技术在熔石英和BK7玻璃基片上镀制了TiO2单层膜、AlO3单层膜以及TiO2/Al2O3增透膜,沉积温度在110℃和280℃.利用X射线粉末衍射仪对膜层微观结构进行了分析研究,并在激光损伤平台上进行了抗激光损伤阈值的测量.采用Nomarski微分干涉差显微镜和原子力显微镜对激光损伤...     

熔石英元件非吸热性杂质对后表面光场的调制

为了研究熔石英元件体内非吸热性杂质导致损伤和光束质量下降,采用时域有限差分法计算杂质散射光场和分步傅里叶算法计算散射光场非线性传输的方法,得到了半径在入射波长量级的气泡和氧化锆杂质可放大光场振幅约1.6和1.9倍,且经非线性传输光场会分裂,调制会加深的结果。结果表明,元件体内杂质可导致元件后表面的损伤和光束质量的下降。     

横流CO2激光器的折叠式谐振腔研究

在横流ＣＯ２激光器中折叠式谐振腔,不仅能改善光束质量,而且有提高转换效率。文章地折叠式谐振腔的折数确定,转折镜的选择,谐振腔的总体结构进行了分析研究,并设计了一种七折光学折叠腔,在大功率横流激光器上取得了良好的实验效果,获得了千瓦级基模激光输出。     

软杀伤战术激光武器及作用机理的研究

光电对抗技术是随着光电技术在军事领域中的广泛应用应运而生的一门崭新学科,而软杀伤激光武器是其中的重要组成部分。软杀伤激光武器作为光电对抗的一种重要手段,在高技术战争中发挥着重要作用,它是以干扰破坏敌方光电系统或致盲、半致盲敌方人员为目的的激光武器,论述了软杀伤武器的作用机理及未来的发展方向。     

钢基表面激光熔覆金属陶瓷涂层的抗磨蚀性能研究

证明了采用ＣＯ２激光熔融预涂覆于钢基体表面的金属陶瓷粉末，能够获得与钢呈冶金结合的金属陶瓷熔覆层。这种金属陶瓷熔覆层与镍基自熔合金粉末的熔覆层比较，抗气蚀和抗磨蚀性能有显著提高。     

无人立尺测量技术在三峡大江截流中的应用

在三峡工程大江截流进程中，随着深水围堰戗堤进占，裹头水位观测的平面位置是一个平行于围堰轴线的动态轨迹。采用无人立尺测量技术代替常规主法接测水中消除堤塌和施工车辆振动等因素对水位精度的影响，并且目标位置可根据需要随时变动。     

激光划切机中工件对准的图像定位方法

针对激光划切机中对LTCC工件定位对准的高精度性要求,对于如何根据工件边角信息进行定位,提出了一种基于对比度增强、Canny双阂值边缘提取和Hough变换的定位方法。将这种图像检测方法应用于激光划切机,工件定位精度小于2μm,满足系统的要求。     

利用BRDF实验测量获取目标表面单位面积激光雷达截面

介绍了一种利用双向反射分布函数实验测量获取目标表面单位面积激光雷达截面的方法,运用双向反射分布函数测量系统在特定激光波长下(1.06μm)对导弹蒙皮和坦克前甲板样片进行实验测量,根据样片的BRDF实验数据,将遗传模拟退火算法应用于目标表面BRDF统计模型的参数反演中,获取样片的BRDF模型参数,然后根据目标表面的双向反射分布函数与单位面积激光雷达截面之间的函数关系,进而可以求出样片的单位面积激光雷达截面的函数表达式.实验数据曲线表明,拟合后的实验数据与参与优化的实验数据吻合得比较好,结果说明用这种方法获取目标表面单位面积激光雷达截面是可行的和有效的.