以綠色化學技術開發低維度氧化鋅奈米材料製備及超臨界二氧化碳清洗反應性離子蝕刻後殘餘物之方法

Green Chemical Approaches toward Preparation of Low Dimensional ZnO and Removal of post-RIE Polymer Residue in Supercritical Carbon Dioxide

羅大倫(Bertrand Lo)

指導教授 ： 凌永健

國立清華大學/理學院/化學系/博士(2007年)

摘要

隨著資源的日漸短缺，工業生產逐漸將環境保護與資源使用效率視為永續發展的核心概念之一。除了傳統的廢棄-回收的簡單低效率技術外，綠色化學更進一步將概念擴展至將能源、物質與時間等資源的高使用/轉換效率，視為減少對環境衝擊的根本方法。因此近年來無論產官學界均逐漸將綠色化學的概念導入各種生產研發過程。
本論文著重於以綠色化學角度開發氧化鋅奈米結構材料，及超臨界二氧化碳流體進行晶圓表面光阻殘餘物的清洗技術等兩部份。首先開發熱裂解法製備出高均勻度氧化鋅奈米粒子（第二章），並利用此高均勻度的氧化鋅奈米粒子進行晶種媒介法而得到高長寬比的氧化鋅奈米柱（第三章）。由於製備過程避免使用多重溶劑，且利用材料本身的特性達到有效控制奈米結構的成果。因此這些技術可以進一步應用於其他類似晶體特性的材料。
第二部份則針對改善高耗水且容易釋放揮發性有機物的半導體清洗製程，由於氯氣電漿蝕刻後易導致光阻本身變質，而在後續的乾式去光阻製程發現移除不完全的現象。本研究即致力於導入超臨界二氧化碳做為氧化降解試劑的分散載體，利用超臨界二氧化碳低表面張力的特性協助反應試劑傳輸至光阻殘餘物表面，並改善反應試劑於兩相間的傳輸效率（第四章）。本文亦提出助溶劑於超臨界二氧化碳中形成液滴的觀點，輔助反應試劑的傳送。並進一步利用蒙地卡羅法模擬液滴的成長與碎裂過程，觀察液滴與樣品表面的接觸效率。研究的結果初步指出助溶劑液滴的概念有助於解釋部份超臨界二氧化碳流體的萃取與反應行為。

關鍵字

超臨界流體 ； 綠色化學 ； 去光阻 ； 氧化鋅 ； 液滴傳輸 ； 晶種媒介法

並列摘要

Owing to lack of the natural resources on Earth gradually, the environmental
protection and the efficiency of resource usage become the core concept for the industrial
production. In addition to the waste recycling techniques, Green Chemistry further
provides the viewpoint of maximizing the usage and transformation efficiency in the
energy, materials, time as a fundamental methodology. Therefore, the fields including
academic, officials, and industrial circles gradually introduce Green Chemistry in the
activities of production and researching.

This dissertation was divided into two distinct sections which the first is the
synthesis of ZnO nanostructures, and the second is the removal of post-RIE (reactive ion
etching) polymer residue by scCO2-assisted oxidative degradation. In the first chapter, the
pyrolysis of zinc acetate dihydrate was used to control the growth of ZnO nanoparticles.
Then, this technique was combined with a seed-mediated method to synthesize the ZnO
nanorods of high aspect ratio (Chapter 3). In addition to avoid using multiple solvents in
the traditional hot soup route, the character of crystal structure was also incorporated in
the oriented growth of nanorods. This technique could be applied to the materials of
similar crystals structures.

The second section was focused on the high consumption of water and organic
solvent in the cleaning process of semiconductor manufacturing. Especially after the
treatment of chlorine plasma etching usually results in the photoresist hard to completely
remove by the oxygen plasma ashing. The third chapter introduced scCO2 as a carrier
medium to assist the oxidative degradation reagent reaching on the surface of post-RIE
polymer residue. The advantage of zero surface tension of scCO2 also improves the
biphasic transportation of oxidative reagent between the cosolvent droplet and the
polymer residue. In the last chapter, Monte Carlo method was introduced to simulate the
possible aggregation and breakage of cosolvent droplets. The surface area of cosolvent
droplets was considered as the index for the contact possibility of oxidative reagent and
polymer residue. The preliminary results demonstrated the instable cosolvent droplets
could be an explanation for the behavior of supercritical fluid and cosolvent in the
extraction and reaction. Our work also provides a framework of researching tool in the
related unstable biphasic process.

並列關鍵字

supercritical fluid ； green chemistry ； photoresist stripping ； zinc oxide ； droplet transportation ； seed-mediated route

參考文獻

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