外加电压对激光电化学刻蚀硅的影响研究

激光电化学刻蚀是将激光加工技术和电化学加工技术有机结合起来而形成的一种复合型刻蚀工艺。为了研究外加电压对激光电化学刻蚀硅的影响,本文采用248nm KrF准分子激光作为光源聚焦照射浸在KOH溶液中的阳极半导体n—Si上,实现激光诱导电化学刻蚀。在实验的基础上,详细分析外加电压对刻蚀工艺的影响,并对其产生的原因进行了分析。试验结果表明其影响主要有两个方面：（1）正的外加电压保证了SiO2钝化膜生成,从而实现了选择性刻蚀;（2）外加电压的增大,刻蚀速率会相应减小。因而外加电压也是调节刻蚀速率的一个重要的手段。     

印刷电路板激光投影成像照明系统均匀性分析

针对351 nm波长的XeF准分子激光器,自行设计了用于高精度、高产率、大面积且常规抗蚀剂曝光的印刷电路板(PCB)激光投影成像照明系统.根据准分子激光的部分相干平顶高斯光束(PCFGB)理论模型,对微透镜阵列器(MLA)均束的衍射特性进行了理论分析.由PCFGB分布函数、稳定光强输出的衍射角和菲涅耳-基尔霍夫衍射积分公式,定量分析衍射效应对MLA均束的影响.理论计算表明,微透镜边缘发生菲涅耳衍射和微透镜产生的多光束干涉都能引起光振幅调制,只不过衍射产生的尖峰更明显地出现在光束边缘.同时,由数值积分得到的PCFGB曲线,发现9×9 MLA均束器既能保证多个微透镜产生光束叠加的均匀性,又最大程度地减少了衍射和多光束干涉效应.通过采取加正六边形光阑的方法,不仅能满足大面积无缝扫描光刻的需要,而且能剪裁由衍射引起的光束边缘尖峰.由ZEMAX光学设计软件模拟其效果,显示其加工窗不大于±2%.     

Preadhesion Laser Treatment of Aluminum Surfaces

An excimer laser may be used for preadhesion treatment of aluminum alloys. This method presents an alternative to the use of ecologically unfriendly chemicals involved in conventional anodizing pretreatments.

Experimental results indicate that preadhesion laser surface treatment significantly improved the shear strength of modified-epoxy bonded aluminum specimens compared with untreated and anodized substrates. The best results were obtained with laser energy of about 0.2 J/Pulse/cm² where single lap shear strength was improved by 600-700% compared with that of untreated Al alloy, and by 40% compared with chromic acid anodizing pretreatment.

The mode of failure changed from adhesive to cohesive as the number of laser pulses increased during treatment. The latter phenomenon has been correlated with morphology changes as revealed by electron microscopy, and chemical modification as indicated by Auger and infrared spectroscopy.

It can be concluded that the excimer laser has potential as a precise, clean and simple preadhesion treatment of Al alloys.     

Excimer laser-induced photochemical modification and adhesion improvement of a fluororesin surface

Modification of a selective area of a fluororesin surface was accomplished by using ArF excimer laser radiation and a boron complex with oleophilic or hydrophilic functional groups. The chemical stability of fluororesin is attributed to the presence of C-F bonds. The F atoms were abstracted by B atoms selectively from the area irradiated with excimer laser radiation and were replaced with the desired functional groups. In this modification, B(CH₃)₃ and B(OH)₃ were used: a boron compound with methyl groups to generate an oleophilic surface, and one with hydroxyl groups to generate a hydrophilic surface. As a result, the resin surface exposed to ArF laser radiation becomes oleophilic or hydrophilic. Both samples were bonded to stainless steel plates with an epoxy bonding agent and the tensile shear strength was 1.2 x 10⁷ Pa in both cases.     

准分子激光均束系统的研究

针对准分子激光的特点,利用透镜阵设计了一种准分子激光均束系统.其能量均匀度误差优于±5%,满足了准分子激光掩模投影加工和激光辐照的光束质量要求.     

XeCl准分子激光器泵浦电参数的优化设计

利用理论模拟方法计算XeCl准分子激光器的激光输出特性,用正交设计方法选择激光器的泵浦电源参数,通过优化分析寻找到了几种可行的最佳泵浦电源参数组合.     

248nm深紫外光刻胶

本文从化学增幅技术的产生，深紫外248nm胶主体树脂及PAG发展历程、溶解抑制剂、存在的工艺问题及解决途径多个方面综述了深紫外248nm胶的发展与进步．     

基于智能的大功率准分子激光器配气与能量的调控

激光器配气和能量调控系统为滞后时间变化的非线性系统, 很难建立准确的数学模型和确定最优解. 根据操作人员对激光器的实际手动控制数据, 提出了辨识模糊控制规则, 给出了基于知识 /推理规则的智能控制方案, 即在获取的知识库引导下, 实现快速响应和较高的控制精度. 该装置具有使用方便, 控制灵活, 误差小等特点, 经过实际使用验证, 工作稳定可靠, 具有较好的实用价值.     

Process study and optimization for fabrication of poly‐Si thin‐film transistors on plastic substrates

Abstract— A complete poly‐Si thin‐film transistor (TFT) on plastic process has been optimized to produce TFT arrays for active‐matrix displays. We present a detailed study of the poly‐Si crystallization process, a mechanism for protecting the plastic substrate from the pulsed laser used to crystallize the silicon, and a high‐performance low‐temperature gate dielectric film. Poly‐Si grain sizes and the corresponding TFT performance have been measured for a range of excimer‐laser crystallization fluences near the full‐melt threshold, allowing optimization of the laser‐crystallization process. A Bragg reflector stack has been embedded in the plastic coating layers; its effectiveness in protecting the plastic from the excimer‐laser pulse is described. Finally, we describe a plasma pre‐oxidation step, which has been added to a low‐temperature (<100°C) gate dielectric film deposition process to dramatically improve the electrical properties of the gate dielectric. These processes have been integrated into a complete poly‐Si TFT on plastic fabrication process, which produces PMOS TFTs with mobilities of 66 cm² /V‐sec, threshold voltages of ?3.5 V, and off currents of approximately 1 pA per micron of gate width.     

Glass: A critical material in the development of electronic displays

Electronic displays may be grouped into two categories, vacuum based and solid state. In both cases, glass has served as the package for the active components making up the display. Thus, glass has often been the limiting factor in the development of these technologies. This paper discusses the interrelationships between the two.