SOI基板上利用SU-8機構組裝之三維微結構

Abstract

近年來在半導體產業的發展之下，微機電製程技術有許多重大的發展，而在許多應用領域中對於三維微結構的要求更是甚多。如何使三維微結構的製造更加有效率且能夠有良好的定位功能是我們的目標。 因為我們所製作的結構最終目標是要應用在光學系統方面，因此採用應力幾乎為零且結構較厚的SOI (Silicon On Insulator)基板製作微鏡面，避免一般利用多晶矽製作時可能發生的翹曲現象，並且整合SU-8以製作其他所需的微結構。由於SU-8有良好的機械特性和低溫製程，使得往後的電路整合更加容易。 我們提出了one-push式的三維微結構組裝方式來簡化組裝複雜度。也就是只要經過一個探針下壓的動作就可以完成組裝。由於結構的定位準確性和結構上的蝕刻孔對於光學上的應用會造成很大的影響，因此我們提出了一種V型絞鏈的新設計來增加組裝結構的定位準確性。另外，為了消除在表面微加工中常出現的蝕刻孔，我們也利用背向乾蝕刻的方式去解決此問題。 在論本文中，我們成功的製造並組裝出上述的元件，其可行性已經獲得證實。而面臨的問題(例如彈簧結構設計不良)和改善方向也將會討論，以利之後對光學系統的製作和電路整合上的要求。

Recently, the Micro Electro Mechanical Systems (MEMS) technology has many important developments with the rapid progress in the semiconductor industry. In many applications, there is demand for three-dimensional (3-D) structures. More effective assembly technique and positioning accuracy are needed for 3-D microstructures. In this thesis, the silicon on insulator (SOI) wafers with almost zero stress are used in order to prevent the stress-induced curvature in micro devices made of poly silicon for optical applications. SU8 has good mechanical property and low temperature process, making it suitable as another structural layer and integration with circuit. In this thesis, a new assembly approach with one push operation is proposed to reduce the assembly complexity. Namely, all probe manipulation is reduced to a simple one-push operation. A novel V-shaped hinge is used to eliminate the play in traditional hinge designs and therefore improves the positioning accuracy. In order to address the issues with etch holes in surface micromachining, the structure without etch holes is used. The etching from the backside of the substrate is performed. The feasibility of the proposed one-push assembly process, V-shaped hinge elements and structure without etch holes, is verified in this thesis. The encountered problems, such as the robustness of spring structures, are discussed for further researches.