創新之雷射干涉微影系統與大面積奈米壓印模具之製作

The Design of a Compact Laser Interference Lithography System for the Fabrication of Large Area Nano-Imprint Mold

楊智翔(Chih-Hsiang Yang)

指導教授 ： 傅建中

國立清華大學/工學院/動力機械工程學系/碩士(2008年)

摘要

為了增進液晶顯示器在光源上的利用率，本文提出以反射式奈米偏光片取代傳統吸收式偏光片，製作上為了達量產目的，可結合奈米壓印微影技術，因此在壓印過程中所使用之奈米模具便扮演著關鍵角色。一般用來製作奈米模具的方式有許多種，如光學微影、電子束微影等技術，而屬於其中技術之一的雷射干涉微影技術則提供了經濟、快速且容易製作奈米結構的優點。為了製作出大面積的奈米結構，一些改良式雷射干涉微影系統被提出來，然而這些改良式干涉微影系統不僅在機構上複雜，且開發成本較高。因此為了快速穩定地製作出大面積奈米模具，本論文的研究目的在於設計出一套符合經濟效益的雷射干涉微影平台，並以拼接方式製作出大面積奈米模具。 雷射干涉微影係利用具同調性雷射光束在空間中干涉，形成光強度週期性分佈現象，並應用於微影技術上來製作週期性結構。首先，我們探討此技術在製程過程中會導致的駐波效應問題，透過Hardmask膜厚設計模型的建立，可以讓我們有效評估Hardmask適當的厚度並搭配抗反射層(ARC)的使用來降低駐波效應的影響。本研究在機構設計上採用Lloyd’s-mirror架構來提升系統穩定性，為了維持奈米移動平台在拼接作業上的精度與穩定度，我們提出以水平式Lloyd’s-mirror機構取代傳統直立式機構，並透過實驗來驗證機構可行性。此外，本研究也針對奈米壓印模具的製程參數、干涉微影機構中所使用的光罩材料、拼接最佳條件做個別探討，來獲得實驗各步驟中的最佳參數。最後，除了在一維奈米週期結構製作外，我們也透過重疊曝光方式，成功製作出二維奈米洞與奈米柱週期結構，藉此說明本機構在符合經濟效益成本上，除了具快速製作奈米模具能力外，也在不同維度的奈米週期性結構製作上具有彈性。

關鍵字

雷射干涉微影 ； 奈米壓印 ； 大面積奈米模具

並列摘要

In order to improve the utilization ratio of light source in LCD display, we propose to replace the traditional absorption polarizer with the reflection nano-polarizer, and combine with nanoimprint lithography technology to achieve the goal of mass production of nano-polarizer. Accordingly, the nanoimprint mold plays a critical role in nanoimprint process. There are many different methods to fabricate the nanoimprint mold, for example, optical lithography, E-beam lithography and so on. Amount these techniques, laser interference lithography provides an inexpensive, rapid and easy way to fabricate nano-patterns. To fabricate high density and large-area nano-patterns, some ameliorated interference lithography systems have been proposed. However, these interference lithography systems are either complicated or expensive. The objective of this study is aimed at designing a compact and cost-effective interference lithography system and by step-and-tiling method to fabricate large-area nanoimprint mold.
Interference lithography is based on the interference of two or more coherent laser beams incident from different directions intersect on a photoresist-coated substrate. The resulting fringes recorded in the photoresist can be used to fabricate 1-D or 2-D period structures. In this study, we first consider the standing wave effect in interference lithography. By establishing a Hardmask design model and combine with the use of ARC, we can reduce the standing wave effect more effectively. The experimental set-up used in this work is Lloyds-mirror . To combine with the two-axis nano-stage and maintain the stability and precision of nano-stage, we designed a horizental-type Lloyd’s-mirror set-up and verified the viability. Besides, to better understand the factors that contribute to the fabrication of nanoimprint mold, we also consider the experiment process recipe, the mask material suit for this set-up, and the optimum condition for tiling. Similarly, a two-dimensional pattern can be generated by superposition of two sinusoidal standing waves with this sep-up. In the consideration of cost-effective condition, the compact interference lithography system not only provides a rapid way to fabricate large-area nanoimprint mold but has the advantage of flexibility in fabricating different dimensional period structures.

並列關鍵字

laser interference lithography ； nano-imprint ； large-area nano-imprint mold

參考文獻

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