准分子激光电化学刻蚀镍的特性研究

提出一种新的准分子激光电化学加工工艺,在阳极钝化区内,通过准分子激光照射,以实现无屏蔽的各向异性的微加工。对该工艺进行了可行性分析,并对其进行了初步试验,证实在钝化区,准分子激光导致刻蚀电流增加的幅度比较明显,在此基础上,深入研究了在准分子脉冲激光作用过程中,刻蚀电流与脉冲数、脉冲频率之间的关系。表明准分子激光在钝化区具有增强电化学特性的能力。     

脉冲激光与电化学复合的应力刻蚀加工质量研究

脉冲激光电化学复合加工可以有效去除激光辐照区域内的电解产物, 提高加工效率, 改善加工质量. 针对高性能金属材料的微细加工要求, 采用脉冲激光电化学复合的应力刻蚀加工方法对铝合金的刻蚀特性进行理论和试验研究. 通过比较激光直接刻蚀加工和激光电化学复合加工的特点, 应用扫描电子显微镜、光学轮廓仪等检测技术分析了刻蚀区域的形貌特征. 根据力学电化学原理, 探讨了金属材料微结构加工的应力去除机理. 通过加工试验, 研究了工艺参数和加工方式对加工质量的影响, 采用优化的工艺参数, 加工出了质量较好的微结构. 试验结果表明, 激光电化学复合的连续扫描加工稳定性好, 可以有效地降低表面粗糙度, 提高加工质量. 关键词： 激光电化学 应力刻蚀 加工质量 工艺参数     

激光应用 激光化学

O644．8 2005053422 准分子激光电化学刻蚀镍的特性研究=Experimental study on characteristic of Ni in excimet-laser induced elec- trochemical etching[刊,中]／周月豪(华中科技大学机械与 工程学院．湖北,武汉(430074)),柳海鹏…∥光学技术．- 2005,31(3)．-323-325,329 提出一种新的准分子激光电化学加工工艺,在阳极钝 化区内,通过准分子激光照射,以实现无屏蔽的各向异性 的微加工。对该工艺进行了可行性分析,并对其进行了初 步试验,证实在钝化区,准分子激光导致刻蚀电流增加的 幅度比较明显。在此基础上,深入研究了在准分子脉冲激 光作用过程中,刻蚀电流与脉冲数、脉冲频率之间的关系。 表明准分子激光在钝化区具有增强电化学特性的能力。 图4参8(严寒)     

308nm准分子激光对C60薄膜的刻蚀特性研究

测量在空气和真空中３０８ｎｍ准分子激光对Ｃ６０薄膜的刻蚀速率和刻蚀阈值，讨论了环境中氧气对刻蚀特性的影响。     

C60薄膜的准分子激光刻蚀及形貌分析

报道了准分子ＸｅＣｌ（３０８ｎｍ）紫外激光刻蚀Ｃ６０膜的实验研究及对刻蚀薄膜的形貌分析。基于形貌分析的结果提出其刻蚀机理。     

短脉冲红外激光诱导等离子体微刻蚀单晶高温高压金刚石

采用短脉冲激光诱导等离子体辅助加工技术加工金刚石微结构,研究短脉冲红外激光的光强、脉宽、重复频率、靶材与金刚石基片之间的距离等加工参数对金刚石的加工线宽、槽深以及加工效果的影响。当用脉冲宽度大于4 ns的激光作用在方向良好的单晶金刚石上时,光热作用明显,诱导产生金属等离子团的能量密度达到一定阈值且复合短脉冲激光能量作用下,单晶金刚石表层温度迅速上升至600°C以上,此时金刚石表层产生了刻蚀微结构;当用脉冲宽度小于4 ns的激光轰击靶材表面时,短脉冲激光轰击靶材诱导金属等离子团,可实现背面溅射相关金属靶材,当等离子体密度达到微刻蚀阈值时也可实现金刚石背部刻蚀以及石墨化。短脉冲红外激光的脉宽、重复频率决定了沉积/刻蚀加工效果。本文研究表明短脉冲激光诱导等离子体辅助加工技术是一种新型可靠的金刚石微结构加工工艺。     

XeCl（308nm）脉冲准分子激光淀积类金刚石薄膜

利用ＸｅＣｌ（３０８ｎｍ）脉冲准分子激光淀积技术在功率密度５×１０８Ｗ／ｃｍ２、室温、真空度１０－３Ｐａ的条件下，制备出不含氢成分的类金刚石薄膜，研究了类金刚石薄膜的特性及其随制备工艺条件的变化规律。研究了激光诱导的碳等离子体发射光谱，探讨了类金刚石薄膜的形成机理。     

非晶硅薄膜太阳能电池的紫外激光刻蚀工艺

为提高电池的光电转换效率,通过改善激光刻蚀工艺,采用355 nm紫外纳秒激光分别进行了ZnO:Al薄膜（AZO）刻蚀（P1）、非晶硅薄膜（-Si）刻蚀（P2）和背电极刻蚀（P3）研究。采用万用表测量P1隔离电阻,采用电子扫描显微镜（SEM）和三维激光扫描仪测量刻槽的微结构和三维成像,激光拉曼散射光谱检测非晶硅薄膜刻蚀边缘的晶化。实验结果表明,当刻蚀速度600 mm/s,重复频率40 kHz,功率1.74 W的紫外激光刻蚀ZnO:Al薄膜时,刻槽的隔离效果最佳,达20 M; 紫外激光刻蚀能够有效地减小激光热效应引起的热影响和刻槽边缘的晶化范围,提高非晶硅薄膜电池的性能。     

缓冲气体对激光等离子体光谱特性影响的实验研究

准分子激光(波长:308 nm,脉宽:10 ns)诱导Al等离子体.详细研究了缓冲气体对激光等离子体光谱特性的影响,测量了不同延时下激光诱导Al等离子体的电子温度和不同缓冲气压下光谱线的Stark展宽并由此计算了等离子体的电子密度,最后根据电子碰撞激发理论对实验结果进行了讨论.     

用308nm准分子激光对几种卷烟用纸打标的研究

激光打标由于具有快速、精度高及非接触等优点，是激光在工业领域的又一应用。准分子激光是一种大功率高重复率的紫外激光器，与ＣＯ２、ＹＡＧ等红外激光相比，一般具有打标效率高、热效应小、图案更精密等优点。近年来国内外均对准分子激光打标进行了一些研究，主要集中在对金属、高分子聚合物及陶瓷等硬脆材料的打标的研究。本文研究了用３０８ｎｍ准分子激光对几种卷烟用纸打标。用适当能量密度的３０８ｎｍ准分子激光对印有数种颜色的烟盒纸、过滤嘴纸打标，获得了清晰可见的图案标记。分析了该打标过程的作用机理，通过实验得出了对几种不同的卷烟用纸打标的能量密度阈值条件及优化条件。     

The study of the solution concentration influencing on laser-induced electrochemical etching silicon

The laser electrochemical etching process, which combines the laser direct etching process and the electrochemical etching process, is a compound etching technique. In order to further understand the solution concentration influencing on the laser-induced electrochemical etching of silicon; a 248 nm excimer laser as a light source and KOH solution as an electrolyte were adopted in this study. The experiments of micromachining silicon by laser-induced electrochemical etching were carried out. On the basis of the experiments results, the solution concentration influencing on the etching rates in the process of laser electrochemical etching of silicon was researched. The reasons of the etching phenomena were analyzed in detail. The experimental results indicate that the solution concentration influencing on the etching process is mainly rooted in the absorption of different concentration solutions to laser. In general, less absorption and low solution concentration are good for the etching role in the process of laser electrochemical etching.     

Thermochemical laser etching of stainless steel and titanium in liquids

Laser-induced wet chemical etching of stainless steel 304 and Ti in phosphoric acid, sulfuric acid and aqueous KOH has been investigated using cw Ar and cw Nd : YAG lasers. Two different phases of laser-induced etching of Ti in phosphoric acid were found by electrochemical investigations. Laser-enhanced electrochemical dissolution of stainless steel was observed in the passivation and transpas sivation region. In the latter case, laser heating accelerates the metal dissolution. In the passivation region, laser heating results in a breakthrough of the passivation layer near the Flade potential. By multiple scanning microstructures of high quality and an aspect ratio > 10 have been produced. By EDX analysis the laser-etching process was found to be practically free of chemical residues on etched surfaces.     

Laser-induced desorption and etching processes on chlorinated Cu and solid CuCl surfaces

Time-resolved mass spectrometry is used to study the desorbed species due to laser-induced etching of a solid CuCl and a chlorinated Cu surface. The observed desorption threshold, mass distribution and kinetic energies of the desorbed atoms and molecules at 355 and 532 nm radiation show that the laser-induced etching process is not simply thermal evaporation. It is suggested that competing nonthermal mechanisms due to electronic excitations may be very important in laser-induced desorption and etching. These processes are different for a solid CuCl and a chlorinated Cu surface. For laser-induced etching of Cu surfaces, chlorination of Cu is essential; however, formation of stoichiometric CuCl is not necessary. Excess Cu in the surface layer is responsible for the observed different etching behavior of a chlorinated Cu and a solid CuCl surface. The effect of laser radiation on these surfaces and possible etching mechanisms are discussed based on the experimental observations.     

预处理对355nm激光作用下熔石英损伤增长的影响

测试了经化学蚀刻、紫外激光预处理及其共同处理后的熔石英355 nm激光损伤阈值;研究了处理前后其损伤斑面积随激光辐照脉冲数的增长情况。结果表明,处理后熔石英355 nm激光损伤阈值得到了提高,且损伤斑面积增长变慢。利用CO2激光对熔石英表面损伤点进行了修复处理,修复后的损伤点R-on-1抗损伤阈值和基底阈值相当,损伤增长得到有效抑制。     

激光刻蚀对镀金表面二次电子发射的有效抑制

使用红外激光刻蚀技术在镀金铝合金表面制备了多种形貌的微孔及交错沟槽阵列.表征了两类激光刻蚀微阵列结构的三维形貌和二维精细形貌,分析了样品表面非理想二级粗糙结构的形成机制.研究了微阵列结构二次电子发射特性对表面形貌的依赖规律.实验结果表明:激光刻蚀得到的微阵列结构能够有效抑制镀金表面二次电子产额(secondary electron yield,SEY),且抑制能力明显优于诸多其他表面处理技术;微阵列结构对SEY的抑制能力与其孔隙率及深宽比呈现正相关,且孔隙率对SEY的影响更为显著.使用蒙特卡罗模拟方法并结合二次电子发射唯象模型和电子轨迹追踪算法,仿真了各微结构表面二次电子发射特性,模拟结果从理论上验证了微阵列结构孔隙率及深宽比对表面SEY的影响规律.本文获得了能够剧烈降低镀金表面SEY的微阵列结构,理论分析了SEY对微结构特征参数的依赖规律,对开发空间微波系统中低SEY表面及提高镀金微波器件性能有重要意义.     

镍金属表面双光束激光干涉直写研究

利用波长为351 nm的半导体抽运全固态脉冲激光器,采用双光束干涉方法,对金属镍板表面直接刻蚀形成微光栅结构的方法进行了实验研究.通过改变激光功率和激光脉冲数等实验参量,研究其对制备的微光栅结构槽形和一级衍射效率的影响.利用扫描电镜和原子力显微镜测量光栅槽形,测得光栅周期为1.25 μm,光栅槽深为10～280 nm,并测量了相应的衍射效率.发现当采用激光单脉冲能量为1.2 mJ,采用10个脉冲加工时,测得槽深为280 nm,一级衍射效率最高（18%）的微光栅结构.利用光栅的衍射理论对衍射效率变化进行了分析.该研究拓展了纳秒激光在加工微结构方面的应用,为在金属材料表面制作纳米压印模版提供了一种新方法.     

Analysis of machining characteristics in electrochemical etching using laser masking

Electrochemical etching using laser masking (EELM), which is a combination of laser beam irradiation for masking and electrochemical etching, allows the micro fabrication of stainless steel without photolithography technology. The EELM process can produce various micro patterns and multilayered structures. In this study, the machining characteristics of EELM were investigated. Changes in characteristics of recast layer formation and the protective effect of the recast layer according to the laser masking conditions and electrochemical etching conditions were investigated by field emission scanning electron microscopy (FE-SEM), focused ion beam (FIB) and X-ray photoelectron spectroscopy (XPS). The oxidized recast layer with a thickness of 500 nm was verified to yield a superior protective effect during electrochemical etching and good form accuracy. Finally, micro patterns and structures were fabricated by EELM.     

Laser-induced etching of silicon

Conventional fabrication method of porous silicon is anodisation of single crystal silicon in hydrofluoric acid. In this report, we show that it is possible to fabricate porous silicon by laser-induced etching. An earlier report by us has demonstrated the dependence of porous silicon photoluminescence characteristic on the etching laser wavelength [1]. Here we used 780 nm line from a diode laser as the etching source, and the optimum etching conditions were obtained. A simple model was proposed to explain the etching process. Scanning Electron Microscope (SEM) images of the samples support the proposed process.