Simple Fabrication of Hierarchical Micro/Nanostructure Superhydrophobic Surface with Stable and Superior Anticorrosion Silicon Steel via Laser Marking Treatment

To improve the weak corrosion resistance of silicon steel to acid solution and alkaline solution with high temperature,a stable hierarchical micro/nanostructure superhydrophobic surface with myriad irregular micro-scale hump and sheet-like nanostructure was successfully prepared on silicon steel by a simple,efficient and facile operation in large-area laser marking treatment.The morphology,composition,wettability of the as-prepared surface were studied.The superhydrophobic performance of the surface was investigated as well.Additionally,the corrosion resistance of the superhydrophobic surface to acidic solutions at room temperature and alkaline solutions at high temperature (80 ℃) was carefully explored.The corrosion resistance mechanism was clarified.Moreover,considering the practical application of the surface in the future,the hardness of the hierarchical micro/nanostructure superhydrophobic surface was studied.The experimental results indicate that the hierarchical micro/nanostructure surface with texture spacing of 100 μm treated at laser scanning speed of 100 mms/ presents superior superhydrophobicity after decreasing surface energy.The contact angle can be as high as 156.6°.Additionally,the superhydrophobic surface provide superior and stable anticorrosive protection for silicon steel in various corrosive environments.More importantly,the prepared structure of the surface shows high hardness,which ensures that the surface of the superhydrophobic surface cannot be destroyed easily.The surface is able to maintain great superhydrophobic performance when it suffers from slight impacting and abrasion.

The Effect of Microstructural and Geometric Inhomogeneities Induced by Laser for Forming Strain Analysis on Sheet Metal Formability

A commercially available laser marking system based on diode-pumped Nd:YVO4 laser was used for creating grid patterns for forming strain analysis of a dual-phase steel. The aim was to determine and analyze the influence of laser working parameters on the formability of sheet material by means of an in-depth characterization of this induced microstructural and geometric inhomogeneity. The electrochemical etching served as the reference method without the negative effect of generating inhomogeneity. The formability was evaluated using the cupping test according to Erichsen. While the quantification of geometric inhomogeneity was based on the determination of the notch factor, light microscopy and microhardness measurement were used for the evaluation of microstructural inhomogeneity. Furthermore, on the basis of the results an empirical regression model was established which described in terms of quantity the relationship between the examined factors such as laser power, pulse frequency and scanning speed as well as the command variable and the mark depth. The results showed that microstructural inhomogeneity in the used marking parameters due to their locally very limited formation did not have an appreciable influence on the mechanical properties. In contrast to this, the induced geometric inhomogeneity had a marked influence on the material formability.

钝化层刻蚀(PAS2)电弧缺陷成因分析及改善方案研究

分析表明,在半导体刻蚀工艺中电弧(Arcing)缺陷一直是难以解决的挑战,尤其是绝缘介质刻蚀如通孔刻蚀、钝化层刻蚀(PAS2)工艺等。电弧缺陷对产品的影响是致命的,通常会造成产品报废,同时这种缺陷在发生的瞬间由于急剧的物理反应将产生大量的颗粒,对腔体造成污染。电弧缺陷的产生跟腔体的RF系统的硬件设计,工艺程式的参数设定、晶圆表面的图形结构、被刻蚀的膜层结构及上下层的连线等诸多因素有关。研究涉及的产品(称为产品A)上钝化层刻蚀(PAS2)工艺在量产过程中长期存在电弧(Arcing)缺陷异常发生率高(万分之六)的问题,远高于万分之一的业界标准。同时绝大部分的电弧缺陷均发生在晶圆Notch方向的Laser Mark结构上。探讨介质刻蚀工艺电弧缺陷的形成机理,并对所在工厂钝化层刻蚀工艺晶圆Laser Mark结构电弧缺陷的成因进行系统性的分析,同时对其解决方案进行详细的分析。