利用自組裝高分子共聚物模板與金屬輔助化學蝕刻製備奈微複合結構之研究

Fabrication of Complex Micro- and Nanostructures using Self-Assembled Diblock Copolymer Templates and Metal-Assisted Chemical Etching

巫宗華(Wu, Zong Hua)

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(2015年)

https://doi.org/10.6843/NTHU.2015.00181

摘要

利用自組裝高分子共聚物來製備規則奈米結構，近年來受到相當大的關注，本論文利用二嵌段聚苯乙烯和聚甲基丙烯酸甲酯(PS-b-PMMA)高分子共聚物經由自組裝來形成規則排列的奈米結構。透過MPTS的自組裝單分子層使得高分子材料和矽基材之間的界面能量中性化，當不對稱(asymmetric)比例的二嵌段高分子經過真空退火後，會微相分離成最密六方的柱狀(PMMA)和網狀(PS)的結構，再經過選擇性蝕刻移除掉PMMA後，就可形成孔洞大小約18奈米，孔洞間距約36奈米的高分子模板。本研究針對表面改質的情況、旋佈高分子轉速的影響以及退火時間長短的控制均有做深刻的討論。
而對體型微加工而言，我們提出了不需要高度真空及高貴的儀器的方法-金屬輔助化學蝕刻。利用金催化的特性以及光阻當遮蔽阻擋蝕刻，並透過HF和H2O2的混合蝕刻液，成功在矽基材上特定的區域進行非等向性蝕刻。此外我們結合了自組裝高分子共聚物模板以及金屬輔助化學蝕刻的結果，利用金粒子在模板孔洞內沉積的效果，在矽基材上蝕刻出和高分子模板相同規則且整齊的奈米孔洞。另一方面，透過模板lift off後產生的鉻粒子陣列當作遮蔽層，我們同樣使用金屬輔助化學蝕刻來蝕刻矽基材，藉此製備出規則排列的矽奈米線結構，更進一步結合黃光微影製程，成功使得矽奈米線結構具有選定的空間分佈。

關鍵字

自組裝高分子共聚物模板 ； 金屬輔助化學蝕刻 ； 奈微複合結構

並列摘要

This thesis presents a novel integration scheme that can fabricate complex micro-nano hybrid silicon structures. The structures are formed by metal-assisted chemical etching, while microlithography and self-assembled diblock copolymer nano- templates are employed to define their geometries. The nano-templates are made of P(S-b-MMA) copolymer that can self-assemble into arrays of 18-nm-diameter PMMA cylinders hexagonally packed in a PS matrix with a lattice constant of 36 nm. To facilitate the self-assembly process, a thin layer of 3-(p-methoxy-phenyl)propyl- trichloro-silane is coated between P(S-b-MMA) and silicon substrate. Once PMMA is selectively removed, the resulting nanoporous PS film is employed to control the deposition of metal nanodots. In the prototype demonstration either chromium or gold is deposited, while chromium and gold is used as the blocking and catalytic material in the etching process, respectively. Meanwhile, photolithography is employed to realize the micro-patterning of metallic thin films. Throughout the process, reactive ion etching is used repeatedly to clean the substrate surface. Finally, the gold-assisted chemical etching is carried out in a solution consisting of deionized water, H2O2, and HF to produce the desired micro-nano hybrid silicon structures. It is demonstrated that the presented integration scheme is a highly repeatable method to form well-aligned, crystalline silicon nanowires with tunable diameters below 100 nm and microstructures as well. As such, the presented integration scheme can fabricate complex micro-nano hybrid structures, which are desired for a variety of cooling and biological applications.

並列關鍵字

Self-Assembled Diblock Copolymer Templates ； Metal-Assisted Chemical Etching ； Complex Micro- and Nanostructures

參考文獻

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