基于复合静电驱动结构的硅微机械扭转微镜

为了改善硅微机械扭转微镜的机电耦合特性,降低器件的驱动电压并提高其工作可靠性,提出了几种新颖的基于复合静电驱动结构的硅微机械扭转微镜.提出的硅微机械扭转微镜将垂直扭转梳齿静电驱动结构、侧壁平行板电容静电驱动结构有机结合,实现了两种静电驱动方式的复合驱动,同时设计了内外双镜面结构,通过内外双镜面结构,实现了微镜的差动复合驱动,理论分析、模拟仿真与测试结果表明,通过上述两个方面新颖的设计,新结构显著降低了器件的驱动电压.同时为了提高器件的工作可靠性,在设计折叠梁柔性支撑结构时,将梁的不同位置设计成不同的厚度,对于硅微机械扭转微镜扭转过程中容易疲劳的梁部分加大了其厚度,从而在不影响器件扭转性能的前提下,明显提高了器件的可靠性.利用有限元方法对器件的力学特性和机电耦合特性进行了系统的仿真,获得了影响器件机电特性的关键结构参数.器件基于SOI晶片,采用表面硅工艺与体硅工艺相结合的方式加工制造,采用SOI晶片显著降低了微镜镜面的表面粗糙度,提高了其光反射能力.最后利用原子力显微镜对微镜镜面的表面粗糙度进行了测量和分析,实验结果表面微镜表面具有16nm的表面粗糙度,完全可以满足光学应用的需要.

Novel MEMS Torsion Micromirror with Compound Driving Structures

Some new kinds of torsion micromirrors with advanced compound driving structures as well as novel folding torsion-spring structures are proposed and fabricated in SOI wafers by combing with bulk micro machining and surface micro machining technology to improve the electromechanical performances and the optical properties of torsion micromirrors. To evaluate the mechanical robustness and the electrical response, the electromechanical performances of the components are investigated experimentally and theoretically. At the same time the surface roughness of the micromirrors is measured and analyzed to characterize the optical properties of the micromirrors. And then some parameters which greatly affect the mirror's total performance are obtained. The theoretical and experimental studies manifest that the compound driving structures and folding torsion-spring structures are much benefit to decreasing the yielding voltages of actuating the micromirrors and, thus, making their tilting motion easier.