- 學位論文
三維磊晶矽微加工製程開發及其於光學微致動器之應用
Development of 3D Epi-micromachining for Micro Optical Actuator
摘要
本文以開發三維磊晶矽微加工製程出發，提出工字形肋與磊晶回填肋補強等三維磊晶矽結構，應用於製作微掃瞄面鏡之元件結構與剛性補強，其中工字形肋補強的特色為整合電化學蝕刻停止與深式反應性離子蝕刻等微加工技術，仿造出巨觀世界常使用的工字樑；而磊晶回填肋補強的特色為利用磊晶矽孔道回填與電化學蝕刻停止等技術，可突破晶格面的限制，製作出非(111)面的磊晶矽結構。接著再整合鈷鎳錳磷硬磁材料當作靜磁力來源，實現一個具鏡面肋補強之靜磁式磊晶矽雙軸微掃瞄面鏡，其特色為：(1)運用三維磊晶矽製程技術，實現高剛性之單晶矽微掃瞄面鏡；(2)運用硬磁材料可免去額外組裝永久磁鐵於元件外部，僅需可提供時變磁場的螺線管，可有效地縮小封裝體積。量測結果可成功地以靜磁力驅動，並可投影出Lissajous掃瞄圖形，驗證了此元件應用於雷射投影顯示之可行性。最後回到磊晶矽晶圓本身具有pn接面的特性，提出光伏式pn接面垂直梳狀致動器，此乃運用光伏效應以雷射光入射元件而產生的靜電力使致動器運動，更進一步可同時以光伏效應與施加逆向偏壓增加其運動振幅。實驗結果可證實此致動概念的可行性，成功地以閃爍雷射光驅動元件於共振模態，並提出四種驅動方式：(1)以閃爍光驅動於共振；(2)閃爍光驅動外加直流逆向偏壓以增加角位移；(3)以逆向方波電壓驅動於共振；(4)逆向方波電壓驅動外加直流光伏電壓以增加角位移。此元件可直接將光能量轉換機械能，在微機電系統的光致動器中是一種嶄新的驅動模式。
並列摘要
This study reports a novel micro electrostatic vertical comb-drive actuator (VCA) driven by the photovoltaic effect that results from incident light. The vertical comb electrodes have a pn junction structure. The VCA with pn-combs can be driven by the photovoltaic effect. The combination of the photovoltaic effect and reverse bias can further increase the driving amplitude of the VCA. To demonstrate the feasibility of the proposed concept, the VCA with pn-combs was fabricated on an epitaxial silicon wafer and successfully driven resonantly by intensity-modulated laser light. The first torsional mode of a typical fabricated VCA is at 1.46 kHz. Moreover, the VCA driven using (1) optical driving, and (2) optical driving with DC reverse bias, were also demonstrated. This study also demonstrates the 2-axis epitaxial silicon scanner driven by the coil-less magnetostatic force using electroplated permanent magnet film. The present approach has four merits: (1) the process employs the cheap silicon wafer with epitaxial layer; and the electrochemical etching stop technique is used to precisely control the thickness of scanner; (2) the I-section rib-reinforced structure is implemented to provide high stiffness of the mirror plate; (3) the magnetostatic driving force on scanner is increased by electroplated permanent magnet film with slender patterns; (4) the size of packaged scanner is reduced since the assembled permanent magnets are not required.