具有次微米尺度結構的自發熱模仁的開發及在成形上的應用

Abstract

結構的微小化以及大面積的成形乃是熱壓微成形的一個重要趨勢。微小化帶給成形品更多的用途，而大面積的成形帶來更大的經濟效益。然而普通的光學微影製程對於結構的微小化至多只能到達微米等級，以普通的熱壓方法也只能使相當有限的區域成形。本研究導入電子束曝光微影的技術，使矽基模仁的結構線寬達到次微米的大小，再利用電漿蝕刻蝕刻出結構深度，並以離子佈植的方法在模仁上製作可通電而使其自發熱的電路，最後藉由使冷卻開始固化的材料再度接近熔融狀態，進而使脫模時的夾持應力降低，減少破壞，改善結構完整性，並促成更大面積的完整脫模成形。 實驗結果顯示，在一般的熱壓成形情況下，次微米結構會有很嚴重的斷裂脫模破壞。而在模仁上通電以施加功率密度的方法確實改善了結構的完整性，並隨著施加更適當的功率密度以及操作時間，慢慢改善其他如傾倒之類的脫模破壞，最後成功達成次微米結構的成形。

The minimization of structure and large-area molding are important trends of hot embossing. Minimization brings products more functions and large-area molding makes much economical benefit. However, normal optical lithography process makes the structure at best achieve micron size and traditional hot embossing can only make limited area molding. In this research, we use E-beam lithography technology to make the line width of silicon-base mold insert structure reach to sub-micron size and then use plasma to etch the depth of structure. Moreover, we implant phosphorous ion into the mold insert to manufacture the circuit which can be charged an electric current to heat the mold insert. Finally, we can decrease the thermal stress, improve the integrity of the structure and make larger area molding during the demolding step by melting the material again which is beginning to solidify. Experiment results demonstrate that sub-micron structure will fracture seriously while demolding in normal hot embossing situation. Applying heat power to the mold insert by charging electric current indeed improves the integrity of the structure. Furthermore, we can improve other demolding defects like slant gradually by applying much appropriate heat power and operating period. Finally, we mold sub-micron structure successfully.