可調控奈米模板之製作與奈微複合結構成型技術之開發

Fabrication of Tunable Nanotemplates for Duplication of Complex Micro- and Nanostructures on Surfaces

張哲瑋(Che-Wei Chang)

指導教授 ： 蘇育全

國立清華大學/原子科學院/工程與系統科學系/碩士(2012年)

摘要

本研究主要是探討調控聚苯乙烯以及聚甲基丙烯酸甲酯(PS-b-PMMA)團聯式共聚物(block copolymer, BCP)的自組裝進行排列形成特定規則的奈米結構。在體積比PS：PMMA = 70：30的二嵌段高分子經過長時間真空退火後會因為微相分離形成網狀(PS)和圓柱狀(PMMA)的結構，再經過浸泡醋酸選擇性移除PMMA後即可形成多孔的奈米模板。而本研究透過多施加大小100V/μm的垂直交流電場來加速結構的組裝，使結構能在電場施加下於ㄧ小時內使孔洞的密度、排列方式與大小能產生出接近真空退火的十二個小時的結果，而電場對於結構的影響在模板厚度較厚時能給予顯著的效果，同時找出奈米模板在交流電場中當頻率為10Hz時會產生直徑25nm，間距60nm的孔洞而且具有最接近六角形最密排列的結構。
另外本研究也探討透過使用HF/AgNO3以及HF/H2O2水溶液搭配鍍有金膜的矽基材進行金屬輔助蝕刻(Metal-assisted chemical etching, MACE)來產生矽奈米結構，並透過實驗得知在金膜厚度大於70nm時所蝕刻出來矽基材的結構會形成平坦的表面，厚度在15nm左右時則會產生奈米線的結構。利用此特性MACE可搭配黃光微影製程，在光阻形成邊長50μm的正方形凹槽陣列中製作矽奈米線結構，因此能夠製造出可以調控的奈微結構。而同時也可透過模板在鍍有金膜的矽基材上組裝的特性，將其製程與金屬輔助蝕刻製程整合，可以得到與奈米多孔模板極性相反高度約20nm的奈米柱結構。除此之外由於此奈米模板的組裝會受到基材表面特性的影響，因此在應用層面希望能夠將此奈米模版的圖形甚至模板本身轉移到其他的基材上，並可以延伸到後續的應用例如微電漿製程、電子零件散熱等用途。

關鍵字

奈米模板 ； 金屬輔助蝕刻 ； 團聯式共聚物

並列摘要

This study presents a tunable nanotemplates of polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) copolymers, which can self-assembly arranged in a regular periodic nanostructure. Diblock copolymer films (20 nm thick) are spin-cast from toluene solutions onto a gold-coated silicon, and annealing the diblock copolymer film for 15min to 1 hour at 180°C under an applied AC electric field then selectively removed PMMA phase by acetic acid to form a densely packed hexagonal pore structure. The AC electric field was accelerate the speed of assembly of diblock copolymer on a gold-coated silicon substrate and when frequency is 100mHz, this pore was 25nm in diameter and center-to-center distance was 60nm which had better arrangement.
Furthermore, this study investigated using metal-assisted chemical etching (MACE) to fabricate nanostructure by using HF/AgNO3 or HF/H2O2 with gold-coated silicon substrate. While the thickness of gold film above 70nm, which could form a flat surface of silicon after etching process. While the thickness of gold was 15nm, which could form a silicon nanowire after etching process. Therefore, the MACE and photolithography process could be integrated to fabricate a structure included complex micro- and nanostructures on surfaces. In addition, we also integrate the process of nanotemplates and MACE to fabricate a 20nm-high nanopillar which has opposite polarity from original template. The assembly of nanotemplate was limited by the surface characteristic, so we continued looking for new method about transferred the pattern of nanotemplate to another substrate.

並列關鍵字

nanotemplates ； metal-assisted chemical etching ； block copolymer ； PS-b-PMMA

參考文獻

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