高分子光分歧器之矽基模仁製作與微熱壓成形研究

Abstract

本研究以多模1x4高分子光分歧器為發展載具，運用MEMS製程之微加工技術製作成4英吋矽基模仁，然後利用微熱壓成形技術對光學等級之高分子PMMA材料進行熱壓成形。整個研究分為矽基模仁製作與微熱壓成形實驗之兩大主軸。在矽基模仁製作方面，利用BeamPROP軟體設計與模擬最佳化之結果，據以製成光罩後進行矽基模仁製程開發，並分別探討微影及非等向蝕刻製程方法及矽基模仁之幾何形狀特性與表面處理。在後續之微熱壓成形實驗則分析主要的製程參數，利用要因實驗及田口實驗計畫法來找尋微熱壓成形參數之顯著控制因子及推定最佳化組合；並探討成形品之微觀缺陷。由研究之結果顯示: 1.製作4英吋矽基模仁以正光阻當蝕刻阻擋層之方法較佳；ICP-RIE乾蝕 刻製程可以獲得良好的幾何形狀精度，但是對於大面積之矽基模仁高 度均勻性控制不佳，需重新考慮製程改善或改用特殊晶圓。 2.應用微熱壓成形機(HEX-03)進行實驗之製程參數中最顯著因子為脫模 溫度，其次為壓印溫度。實驗推定最佳化控制因子組合為壓印溫度 120℃、壓印力32,500N、壓印時間270 sec及脫模溫度70℃；經實驗驗 證符合所預測之95%信賴區範圍。

This research focuses on the manufacturing of multimode polymer splitter. MEMS fabricating process was first adopted for the fabrication of four inches silicon mold insert and then the micro hot embossing technique was applied on optical class PMMA material to make splitters. Complete thesis is divided into two topics, which include silicon mold insert fabrication and micro hot embossing process. In the design of optimal silicon mold insert mask the BeamPROP software was used. Investigations were then focused on Lithography and non-isotropic etching process, as well as micro channel’s geometry and anti-adhesive thin films treatment on the surface of mold insert. In the topic of micro hot embossing analysis, the factorial experiment and Taguchi method were used to find the most significant control factor and the optimal combination of micro hot embossing parameters. The geometry characteristics and micro defects that can affect the performance of the finished products were also discussed. The above study concluded, 1.Silicon mold insert fabricated by using positive resistance etching stop layer is most suitable, while ICP-RIE is not suitable for mold insert with large area because of the non- uniformity of depth control. 2.The most significant control parameter in the micro hot embossing process is de-molding temperature, followed by the embossing temperature. The optimal combination of process parameters are embossing temperature of 120℃, embossing forces of 32,500N, embossing time of 270sec and de-molding temperature of 70℃。