Study on reflection type display using micro actuator

研究了利用法布里-珀罗（FPI）干涉仪进行彩色显示的方法。该显示器具有简单的矩阵结构，其中显示像素形成在纵向电极和垂直电极的交叉处。制作过程是表面微加工技术，适用于精确控制干涉仪的两个（活动和固定）反射镜之间的腔长。为了显示全色，在所有像素处将FPI与红色、绿色和蓝色的滤色器组合。为了设计合适的器件结构，从理论上研究了干涉仪的机电特性以及器件参数与彩色显示特性的关系。镍被用作反射镜材料，并且用于VLSI的高耐热性精细聚酰亚胺被用于牺牲层，因为其蚀刻剂不侵蚀反射镜材料。接下来的技术被建立;聚酰亚胺牺牲层和氮化硅图案的可移动的反射镜上的牺牲层的形成，以及通过去除牺牲层的氮化硅的可移动的反射镜图案和固定的反射镜之间的薄腔的形成。为了形成可移动反射镜，氮化硅层和非常薄的镍层被堆叠，并且这些层通过蚀刻被图案化。然而，由于在台阶部分处的电极的图案和切割的损坏，不能形成期望的可移动反射镜（微致动器的可移动电极）。我们希望在审查了可移动反射镜的材料、膜厚、沉积方法和沉积条件之后继续制造显示器。

A color display using the Fabry-Perot (FPI) interferometer was studied. The display had a simple matrix structure in which display pixels were formed at intersections of longitudinal electrodes and perpendicular electrodes. Fabrication process was the surface micromachining technology which is suitable for an accurate control of the cavity length between two (movable and fixed) mirrors of the interferometer. To display full colors, FPIs were combined with color filters of read, green, and blue at all pixels. To design the suitable device structure, electromechanical behaviors of the interferometer and relationships between various device parameters and color display characteristics were studied theoretically. Nickel was used as the mirror material and high heat-resistance fine polyimides for VLSI was used to sacrificial layers because its etchant does not attack the mirror material. The next technologies were established ; formations of the polyimides sacrificial layer and the silicon nitride patterns of movable mirror on the sacrificial layers, and formation of thin cavities between the movable mirror patterns of silicon nitride and the fixed mirrors by removing the sacrificial layers. To form the movable mirrors, silicon nitride layers and a very thin nickel layer were piled and these layer were patterned by etching. However, desirable movable mirrors (movable electrodes of micro actuators) could not be formed because of damages of patterns and cuttings of the electrodes at the step portions. We want to continue fabrication of the display after reviewing the materials, film thickness, deposition methods and deposition conditions of the movable mirrors.