Development and evaluation of fabrication method of functional surfaces for MEMS

为了给MEMS接触面和滑动面提供新的功能，研究了超低摩擦、低磨损率、低弹跳高度滑块的制造新方法。得到了以下原理结果。(1)为了使类金刚石碳的滑动表面具有超低摩擦和低磨损的性能，提出了一种利用表面波激发等离子体高速涂层类金刚石碳的新方法。用蓝宝石天线在金属管上涂上DLC。其硬度为21 GPa。其厚度沿管道方向偏差在15%以内。管材温度是控制DLC结构和力学性能的重要参数。(2)为了控制微滑块在滑动过程中的弹跳高度，提出了一种在滑动表面制造微凸起的新方法。采用离子束辐照制备微凸起，凸起高度应小于100nm。聚碳酸酯在数nm高度表现出均匀的凹凸不平。辐照高度受辐照离子、等离子体种类和辐照周期的控制。研究了微花纹对摩擦性能的影响。少量的缸高微纹表明，摩擦与滑动速度无关。(3)为了评估滑动表面的局部表面能，测量了微凝聚液滴的接触角。通过这种方法，证实了多相金属中作为一个金属相的局部表面能不同于各个金属相的单独表面能。结果表明，切削条件不仅改变了单晶硅的表面粗糙度，而且改变了表面能。

In order to provide the new function to the contact and sliding surfaces for MEMS, it was investigated of the new fabrication method with ultra low friction, low wear rate and low bouncing height slider. The following principle results were obtained.(1) In order to provide the ultra low friction and low wear properties to the sliding surface, a new high speed coating method of Diamond-like Carbons was developed by using surface wave excited plasma. A metal pipe was coated with DLC by using a sapphire antenna. The its hardness was 21 GPa. The its deviation of the thickness was within 15% along the pipe. The temperature of the pipe was considered as the important parameter to control the structure and mechanical properties of the DLC.(2) In order to control the bouncing height of a tiny slider during sliding, a new fabrication method of micro asperities on the sliding surface was proposed. Ion-beam irradiation were used to make micro asperities because the heights of those asperities should be less than 100 nm. The Polycarbonate showed uniform asperities in several nm height. The height was controlled by the irradiation ion and plasma species and irradiation period. The effect of the micro patterns on the friction properties was investigated. A few urn height micro pattern showed that, the friction was independent of the sliding velocity.(3) In order to evaluate local surface energy on the sliding surface, the contact angle of micro condensed liquid drops were measured. By using this method, it was confirmed that the local surface energy as one metal phase in the multi-phase metal was different from the individual surface energy of each metal phase. Also it was confirmed that the cutting condition for the single crystalline Silicon changed not only surface roughness but also surface energy.