氮化鎵被認為是繼矽之後最重要半導體材料，目前主要是以磊晶的方式成長於藍寶石或碳化矽基板，並已廣泛應用於高功率藍白光LED的量產。將氮化鎵磊晶於矽基板上將是未來的新趨勢，近期並將應用於高電子移動速度電晶體的製作。但因氮化鎵與矽基板之晶格差異而產生後續磊晶缺陷或熱變形問題，其中最重要的解決方案之一便是圖案化技術。圖案化矽基板用於改善矽基氮化鎵的磊晶問題、提高其出光效率及改善其吸光問題。以往圖案化技術均沿用傳統半導體製程所用之微影製程，然而，以此製程製作圖案化基板無法達到產業所需之更微細結構、更低生產成本之目的。
本研究嘗試採用氣體輔助奈米轉印技術取代傳統微影技術。PDMS具有可撓性，在轉印時可克服非平面基材在均勻壓力及接觸之問題。氣體具有均勻且等向之特性，在大面積及非平面基材上施壓具有良好的效用。本研究使用PDMS做為模具材料、氮氣為轉印壓力源在矽基板上轉印出光阻結構，再使用蝕刻技術成功在矽基板上製作平整結構。

This study is to develop the manufacturing technology of patterning on Silicon substrate for high power GaN (Gallium Nitride) devices. Patterning problem is the most important and major issue of epitaxial growth of GaN on Silicon. The stepper lithography is usually employed or modified for the periodical patterning processing, but it can not meet the industrial demand for high resolution pattern fabrication with low cost and high throughput.
This study tries to use gas-assisted imprinting instead of stepper lithography. Gas-assisted design can achieve pressure uniformity and isotropic, and it is suitable to large area product fabrication. The imprinting molds’ material used in this study is PDMS (Polydimethylsiloxane). Due to the special properties of PDMS the molds are flexible and can be replicated easily. It is expected according to these two settings a fabrication process for large area patterned silicon substrate manufacturing with low cost, high throughput and nano scale resolution features can be achieved and proved.

[1]. Nanotechnology and MEMS: Commercializing Ultra-Small Objects—Market,Opportunities and Technologies, Published by Takeda Pacific, May 2002.
[2]. S. Y. Chou, P. R. Krauss, and P. J. Renstorm, “Imprint of sub-25 nm vias and trenches in polymers”, Applied Physics Letters, vol. 67, pp. 3114-3116, 1995.
[3]. S. Y. Chou, P. R. Krauss, and P. J. Renstorm, “Nanoimprint lithography”, Journal of Vacuum Science & Technology B, vol. 14, pp. 4129-4133, 1996.
[4]. S. Y. Chou, P. R. Krauss, W. Zhang, Lingjie Guo, and Lei Zhuang, “Sub-10nm imprint lithography and applications”, Journal of Vacuum Science & Technology B, vol. 15, 2897, 2007.
[5]. K. J. Morton, G. Nieberg, S. Bai, S. Y Chou, “Wafer-scale patterning of sub-40 nmdiameter and high aspect ratio (>50:1) silicon pillar arrays by nanoimprintand etching”, Nanotechnology, vol. 19, pp. 1-6, 2008.
[6]. N. S. Ong, Y. H. Koh, Y. Q. Fu, “Microlens array produced using hot embossing process”, Microelectronic Engineering, vol. 60, pp. 365-379, 2002.
[7]. Y. Hirai, Y. Onishi, T. Tanabe, M. Shibata, T. Iwasaki, Y. Iriy, “Pressure and resist thickness dependency of resist time evolutions profiles in nanoimprint lithography”, Microelectronic Engineering, vol. 85, pp. 842-845, 2008.
[8]. M. Bender, M. Otto, B. Hadam, B. Vratzov, B. Spangenberg, and H. Kurz, “Fabrication of Nanostructures using a UV-based imprint technique”, Microelectronic Engineering, vol. 53, pp. 233-236, 2000.
[9]. H. Lee and G. Y. Jung, “UV Curing Nanoimprint Lithography for Uniform Layers and Minimized Residual Layers,” Japanese Journal of Applied Physics, vol. 43, pp. 8369-8373, 2004.
[10]. Zhuwei Li, Yanni Gu, Lei Wang, Haixiong Ge, Wei Wu, Qiang Xia, Changsheng Yuan, Yanfeng Chen, Bo Cui, and R. Stanly Williams, “Hybrid Nanoimprint-Soft Lithography with Sub-15nm Resolution”, NANO LETTER, vol. 9, pp. 2306-2310, 2009.
[11]. He Guo, Hua Tan, Wei Zhang, Keith Morton, and Stephen Y. Chou, “Air cushion press for excellent uniformly,high yield,and fast nanoimprint across 100 mm field”, NANO LETTER, vol. 6,pp. 2438-2441, 2006.
[12]. B. Farshchian, A. Amirsadeghi, S. M. Hurst, J. Wu, J. Lee, and S. Park, “Soft UV-nanoimprint lithography on non-planar surfaces,” Microelectronic Engineering, vol. 88, pp. 3287-3292, 2011.
[13]. J. H. Chang, S. Y. Yang, “Gas pressurized hot embossing for transcription of micro-features”, Microsystem Technologies, vol. 10, pp. 76-80, 2003.
[14]. J. H. Chang, F. S. Cheng, C. C. Chao, Y. C. Weng, S. Y. Yang, “Direct imprinting using soft mold and gas pressure for large area and curved surfaces”, Journal of Vacuum Science & Technology A , vol. 23, pp. 1687-1690, 2005.
[15]. J. H. Chang, S. Y. Yang, “Development of fluid-based heating and pressing systems for micro hot embossing”, Microsystem Technologies, vol. 11, pp. 396-403, 2005.
[16]. J. h Jeong, K. D. Kim, Y. S. Sim, H. Sohn, E. S. Lee, “A step-and-repeat UV-nanoimprint lithography process using an elementwise patterned stamp”, Microelectronic Engineering, vol. 82, pp. 180-188, 2005.
[17]. H. Gao, H. Tan, W. Zhang, K. Morton, S. Y. Chou, “Air cushion press for excellent uniformity, high yield, and fast nanoimprint across a 100mm field”, Nano Letters, vol. 6, pp. 2438-2441, 2006.
[18]. F. S. Cheng, S. Y. Yang, C. C. Chen, “Novel hydrostatic pressuring mechanism for soft UV-imprinting processes”, Journal of Vacuum Science & Technology B, vol. 26, pp. 132-136, 2008.
[19]. J. I. Pankove, ”Gallium Nitride (GaN) I”, Academic press, San Diego,1998.
[20]. 史光國編著”現代半導體發光及雷射二極體材料技術”,全華科技圖書,2001.
[21]. S. Zamir, B. Mayler, J. Salzman, “Lateral confined epitaxy of GaN layers on Si substrates”, Journal of Crystal Growth, vol. 230, pp. 341-345, 2001.
[22]. Dongmei. Deng, Naisen Yu, Yong Wang, Xinbo Zou, Hao-Chung Kuo, Peng Chen, and Kei May Lau, “InGaN-based light-emitting diodes grown and fabricated on nanopatterned Si substrates”, Applied Physics Letters, vol. 96, 201106, 2010.
[23]. T. Hikosaka, T. Tanikawa, Y. Honda, M, Yamaguchi, and N. Sawaki, “Fabrication and properties of semi-polar(1-101) and (11-22) InGaN/GaN light emitting diodes on patterned Si substrates”, physica status solidi (c), vol. 5, pp. 2234-2237, 2008.
[24]. S. M. Sze and G. Y. Chang, “ULSI Technology”, McGraw-Hill, 1996.
[25]. P. J. Holmes, The Electrochemistry of Semiconductors, Academic press, 329, 1962.
[26]. J. H. Chang, S. Y. Yang, “Gas pressurized hot embossing for transcription of micro-features”, Microsystem Technologies, vol. 10, pp. 76-80, 2003.
[27]. 林雅玲, “感應耦合式電漿蝕刻技術對氮化鎵的蝕刻研究” , 中原大學碩士論文, 民國90年6 月.
[28]. Arystal, 2007, <www.arystal.co.kr>.
[29]. Shuhuai Lan, Hye-Jin Lee, EunHee Kim, Jun Ni, Soo-Hun Lee, Xinmin Lai, Jung-Han Song, Nak Kye Lee, Moon G. Lee, “A parameter study on the micro hot-embossing process of glassy polymer for pattern replication”, Microelectronic Engineering, vol. 86, pp. 2369-2374, 2009.
[30]. D. M. Whitesides, Y. Xia, “Soft Lithography”, Angew. Chem. Int. Ed., vol. 37, pp. 550-575, 1998.
[31]. Weimin Zhou, “Nanoimprint Lithography:An Enabling Process for Nanofabrication”, Springer, 2013.