以光感高分子材料製作垂直梳狀致動器

Abstract

垂直式梳狀致動器是微機電最著名的元件之ㄧ。至今為止，所有被發展出 來的垂直式梳狀致動器多以矽(或多晶矽)作為主要結構材料，然而，這些必 須由深反應離子蝕刻(DRIE)進行加工，或以SOI 晶片為主的技術，雖然高 精度，也意味著較高的製作成本。相對於矽基材料，高分子正成為極具吸 引力的替代性材料，除了製作成本較低外，其低溫製程也易與其他元件製 程整合。然而至今尚未有文獻利用高分子材料製作垂直式梳狀致動器。本 實驗室近年開發出一可對正型光阻進行雙面多重部分曝光(DoMPE)的製程 平台，可建構雙面多階高度的懸浮正型光阻結構，且不需額外犧牲層材料。 本計畫即是希望進一步以此製程平台技術，結合表面金屬沉積技術，製作 以正型光阻為結構材料的高分子垂直式梳狀致動器。另外，也由於負型光 阻SU-8 具有優異機械強度特性，本計劃另一重點即是希望開發負型光阻的 雙面多重部分曝光的製程平台，並以此製程平台製作以SU-8 為結構材料之 高分子垂直式梳狀致動器。本計劃規劃為兩年期計畫，第一年重點在設計、 製作與量測以正型光阻為結構材料的高分子垂直式梳狀致動器，並建立負 型光阻的雙面多重部分曝光製程平台的關鍵參數，第二年重點在完成負型 光阻的雙面多重部分曝光製程平台，及設計、製作與量測以負型光阻為結 構材料的高分子垂直式梳狀致動器，並探討比較兩者特性。

Vertical comb drive (VCD) is one of the most famous components in micro electro mechanical systems (MEMS) due to its superior characteristics in out-of-plane motion. To date, most of the reported VCDs were fabricated by silicon-based micromachining using silicon-based materials as the main structural material, and exhibit a high cost solution by the DRIE process or SOI-wafers. In contrast to silicon, the polymer is becoming an attractive alternative, not just for its low cost, but also for its integration capability with other components due to the low-temperature process. However, no polymer -based VCD has been reported yet. Our research group recently has developed a double-side multiple partial exposure (DoMPE) process to enhance the complexity of the suspended microstructure made of positive photo resist. By combining metal deposition technology, one of the goals in this proposal is to fabricate the polymer vertical comb drive made of positive photo resist using the DoMPE process. Since the negative photo resist, SU-8, is famous for its excellent material properties, here the DoMPE process for negative photo resist will be further investigated, and acted as the fabrication method for the polymer vertical comb drive made of negative photo resist. The investigation is proposed to be a two-year plan. In the first year, the main objective will be the design, fabrication, and testing of the polymer vertical comb drive made of positive photo resist, and establishment on key process parameters in negative photo-resist DoMPE process. In the second year, DoMPE process for positive and negative photo resists will both be established and compared. Also, the polymer vertical comb drive made of SU-8 will be designed, fabricated, and characterized.