Applying High Aspect Ratio BELST Process in Vertical Actuated Electrostatic Micro Scanning Mirror

• Main Authors: Chien Cheng Chu, 朱健誠
• Other Authors: Weileun Fang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/79226695404888051037

碩士 === 國立清華大學 === 動力機械工程學系 === 90 === Angular motion plays a crucial role in optical applications such as switching and scanning. The angular motion is available using electrostatic actuation like parallel plate, lateral comb, and vertical comb. Among them the vertical comb actuator (VCA) is regarded as the most promising approach to provide large angular motion. Recently, the High-Aspect-Ratio micromachining (HARM) process have demonstrated their importance of offering even large angular motion as well as extremely stiffness micro-structures. However, these approaches may suffer from alignment and bonding processes. A HARM process using (111) silicon wafer is proposed in this study to fabricate a vertical comb drive actuator and a micro scanning mirror. Moreover, a large yet stiff mirror and a thin torsional spring are also available through the Extended BELST process within three masks. Thus the optical performance is improved and the driving voltage is reduced. A high-aspect-ratio micro scanner embedded with vertical comb actuator, 500×500mm2 flat mirror, and trimmed torsional springs is successfully fabricated. The static and dynamic performances of micro scanner are also measured.