- 學位論文
以全圖案模仁壓印微奈米金光柵之成型性分析
Direct Micro/Nanoimprint and Fidelity Analysis with Full Patterns Grating
摘要
製作LCD背光模組中具偏振功能的複合線光柵偏振片(Composite Wire Grid Polarizer)乃是直接金屬奈米壓印法(Direct metal nanoimprint)成功後最終目的，而隨著半導體技術的蓬勃發展，舉凡像是化學研磨、蝕刻等該技術中的後段製程早已穩定，因此影響此製程最關鍵的步驟是在直接金屬奈米壓印中金屬材料能夠大面積地完整複製模仁上的奈米級圖案，若成功實現該製程即可以取代半導體產業普遍使用的黃光微影製程，將微影製程繁複的步驟簡化，可大幅提升產量，降低製作成本。 本研究以常見的黃光微影製程製作圖案(7 × 7 mm2)柵狀線寬470 nm周期800nm的矽模仁，以鍍著在矽基板上的300nm金薄膜作為壓印層，在120℃下以負荷4300 kg進行直接金屬奈米壓印，試圖製作出全圖案且均勻的光柵圖案，結果發現邊緣光柵成型性較中央佳，金光柵成型高度不平均的現象。 為探討中央區域圖案成型性不佳的原因，利用有限元素SIMUFACT模擬軟體再帶入實驗邊界條件作為基礎，由於本研究中的直接奈米壓印其模具、材料屬於多尺度，因此建立簡化模型及多齒模型來證實其可行性，分析金薄膜、模仁、背襯墊的變形狀態及受力狀態，解釋發生邊緣及中央成型不均勻的因果，從中得知模仁發生彈性變形導致其模齒部份邊緣壓深較深及金薄膜流動不均，以至於光柵成型高度不均勻。
並列摘要
The goal of direct nanoimprint process is to fabricate bi-layered metallic wire-grid polarizers (WGP). The most critical process of this fabrication is how to transfer full and large nano-pattern from mold to imprinted material. If this process works, this technique which will surpass the photolithography technology and offers a low-cost, time-saving, and straightforward patterning process to produce gold gratings. A 7 mm2 Si mold with full grating pattern is prepared using conventional photolithography. We try to transfer the mold pattern to the 300 nm Au film in nanoimprint at 4300kg/120oC/5min, but the uniformity of the imprinted pattern is poor. The grating exhibited better fidelity near the pattern edge than in the center. To postulate the possible reasons for the poor patterning at the central region of the mold, the stress and deformation distribution in mold, gold film, and upper backing plate were computed using finite element method (FEM) under experimental boundary conditions. Since direct nanoimprint is a multiscale process, two different models in millimeter scale were established. We try to explain the material flow of Au film and mold deformation by FE analysis. Furthermore, the results show elastic deformation of mold teeth and upper backing plate near the edge. On the other hand, FE analysis on the material flow during embossing reveals non-uniform equivalent stress along x-and z- directions on Au film.