CMP流场的数值模拟及离心力影响分析

化学机械抛光(chemical mechanical polishing,CMP)是一项融合化学分解和机械力学的工艺,其中包含了流体动力润滑的作用.在已有润滑方程的基础上,提出并分析了带有离心力项的润滑方程.利用Chebyshev加速超松弛技术对有离心力项的润滑方程进行求解,得到离心力对抛光液压力分布的影响.数值模拟结果表明,压力分布与不带离心力项的润滑方程得出的明显不同;无量纲载荷和转矩随中心膜厚、转角、倾角、抛光垫旋转角速度等参数的变化趋势相同,但数值相差较大,抛光垫旋转角速度越大差别越大.

块体非晶合金在低温下的剪切带特征

通过宏观洛氏压痕实验在低温(193K)下对玻璃转变温度和本征脆性具有显著差别的5种典型非晶合金(Mg65Cu25Gd10,La55Al25Cu10Ni5Co5,Pd43Cu27Ni10P20,Zr47.9Ti0.3Ni3.1Cu39.3Al9.4,Fe52Cr15Mo9Er3C15B6)的剪切带特征进行了研究。考查了剪切带间距和数量与归一化温度和材料本征脆性的关联,并根据放射状剪切带的夹角讨论了不同合金的压力敏感系数及其影响因素。

An Instrumented Indentation Method for Young's Modulus Measurement with Accuracy Estimation

The relationships between indentation responses and Young's modulus of an indented material were investigated by employing dimensional analysis and finite element method. Three representative tip bluntness geometries were introduced to describe the shape of a real Berkovich indenter. It was demonstrated that for each of these bluntness geometries, a set of approximate indentation relationships correlating the ratio of nominal hardness/reduced Young's modulus H (n) /E (r) and the ratio of elastic work/total work W (e)/W can be derived. Consequently, a method for Young's modulus measurement combined with its accuracy estimation was established on basis of these relationships. The effectiveness of this approach was verified by performing nanoindentation tests on S45C carbon steel and 6061 aluminum alloy and microindentation tests on aluminum single crystal, GCr15 bearing steel and fused silica.

Annealing effects of sapphire substrate on properties of ZnO films grown by magnetron sputtering

The annealing effects of sapphire substrates on the quality of epitaxial ZnO films grown by dc reactive magnetron sputtering were studied. The atomic steps formed on (0001) sapphire (alpha-Al2O3) substrates surface by annealing at high temperature were analyzed by atomic force microscopy. Their influence on the growth of ZnO films was examined by X-ray diffraction and photoluminescence measurements. Experimental results indicate that the film quality is strongly affected by annealing treatment of the sapphire substrate surface. The optimum annealing temperature of sapphire substrates for ZnO grown by magnetron sputtering is 1400 degrees C for 1 h in air.

Ta2O5膜在532, 800 和 1064 nm波长的n-on-1体系下的激光损伤阈值研究

Ta2O5膜采用传统的电子束蒸发方法制备，并在氧气中673 K的条件下进行了退火12 h处理。首先在1-on-1体系下对Ta2O5膜进行了532和1064 nm波长下的激光损伤阈值（LIDT） 研究，然后在n-on-1体系下分别对532，800和1064 nm三种波长下的激光损伤阈值进行了研究。结果表明在n-on-1体系下Ta2O5膜在532和1064 nm波长下的阈值均高于1-on-1体系下的阈值。此外，在n-on-1体系下，薄膜的阈值随波长增加而增大。同时发现，在氧气中进行退火对Ta2O5膜的光学性能