奈米多孔陽極氧化鋁膜於微機電顯示元件開發之研究

Design and Implementation of MEMS Display Devices Using Nanoporous Anodic Aluminum Oxide Layer

羅珮瑄(Pei-Hsuan Lo)

指導教授 ： 方維倫

國立清華大學/工學院/奈米工程與微系統研究所/博士(2014年)

摘要

奈米多孔陽極氧化鋁在奈微米領域之中經常被當作模板功能的使用，但其具有可調控之材料特性，包括調變薄膜孔隙率可控制其光學折射率、介電係數與楊氏模數等，具有潛力可以被延伸應用至模板功能以外的微機電元件發展。因此本論文利用微機電製程技術，製作微小尺寸、批量化且可重複製程，整合奈米多孔陽極氧化鋁於微機電光學元件的應用，透過開發干涉調節光學顯示像素可以有效發揮奈米多孔陽極氧化鋁膜之優越特性。透過兩階段成長陽極氧化法步驟定義奈米多孔陽極氧化鋁於矽基板，且經過多道微機電製程技術，調變奈米多孔結構以完成具有光學、機械與電學特性之微元件。本論文所開發之干涉調節光學元件具有下列特性：(1) 奈米多孔陽極氧化鋁膜之光學折射率可經由製程參數輕易調控，可增加光學設計之靈活度，(2) 利用奈米多孔陽極氧化鋁膜可調孔隙率之特點，可設計紅綠藍三原色像素分屬的折射率，因此不需要定義三種厚度的共振腔長，元件將共享同一層犧牲層，使得製程更容易達成，(3) 藉由低溫自組織奈米孔洞的結構，可以有效降低膜層之間的接觸面積，降低致動時的黏附 (in-use stiction)現象發生，增進元件的可靠度，(4) 介電層電荷累積 (dielectric charging)現象可以有效的被奈米多孔陽極氧化鋁膜抑制，減少元件驅動時的電壓偏移量，(5) 改變奈米多孔陽極氧化鋁膜的孔隙率，可以明顯調控驅動電壓，以及(6) 鋁半反射層沉積在多孔隙氧化鋁膜的上方所形成的奈米顆粒，具有光擴散的功能，可以增加光學顯示元件可視角範圍。藉由本論文所提出干涉調節光學顯示像素元件的開發，可以進一步為奈米多孔陽極氧化鋁找尋新的應用與發展方向。

關鍵字

奈米多孔陽極氧化鋁 ； 微機電 ； 顯示像素 ； 干涉

並列摘要

Nanoporous anodic aluminum oxide (np-AAO) exists tunable material properties in application of various researches. This dissertation developed batch and reproducible np-AAO technology by micro/nano fabrication processes in order to applied electrical, optical, and mechanical properties of np-AAO into micro devices. This study further presents the use of np-AAO for interferometric color pixel application. The merits of this np-AAO color pixels are as follows, (1) porosity of np-AAO layer can be easily adjusted by fabrication process to modulate the refractive index of proposed device, (2) color-pixels of different porosities (refractive indices) can be implemented and integrated on single np-AAO layer by process for different colors modulation, (3) in-use stiction of the actuation np-AAO membrane can be reduced by the nanoporous textures, (4) dielectric charging can be largely reduced by np-AAO material in this study, thus the offset voltage of the polarities close to zero and hysteresis curves are symmetric, (5) driving (pull-in) voltage can be reduced due to superior dielectric constant of np-AAO, and (6) in addition, the morphology of np-AAO with Al half-reflector could scatter the reflect light to further enhance the view-angle of the color-pixels. The tests demonstrate the performance of presented np-AAO for interferometric color pixels.

並列關鍵字

Nanoporous anodic aluminum oxide ； MEMS ； Color pixel ； interference

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