本研究主要針對 EAPSM 光罩清洗流程進行探討，尋求可降低霧 狀污染形成的清洗方式，同時延長光罩的使用壽命。從離子殘留程度 及相損失程度、光穿透度進行比較，在眾多無硫清洗方法（Sulfate free cleaning）中，以 DUV 搭配熱處理方式對於消滅 DUV 光罩的霧狀污 染最為適切。
選擇不使用傳統法，可大大降低超純水的使用量，且 DUV 產生臭 氧的方式屬於乾式法，使用的化學品也大幅減少，對於環境負荷減少，
友善度提高，對企業而言，可望達到清潔生產。惟需加熱至 200℃，
所產生的溫室氣體，其碳足跡是否會抵銷前述因用水及化學品減量的 優勢，且昇華的硫酸銨後續處理，尚有探討空間。
本研究提到目前發展方向多以臭氧取代硫酸為主，需特別注意的 是，臭氧對於金屬的傷害，因 EUV 光罩使用了大量的金屬類化合物，
例如釕 Ru，在方法導入前期，則須加入考量。
本研究從諸多光罩清潔方法中，以前述分析手法，獲得最為適切 的清洗方法。並在研究中比較各清洗單元的特性，在接下來的微影製 程技術無論是走到 193 nm 浸潤式（immersion）微影技術或是極紫外 線（EUV）微影技術，皆可參考各界對於 193nm DUV 光罩清洗方法 的成果，為下一代製程節點作好準備。
參考文獻
〔1〕 Grenon, B.J. , Peters, C. , Battacharyya, K. and Volk, W.,
“Formation and Detection of Sub-pellicle Defects by Exposure to DUV System Illumination”, Proceedings of SPIE Vol. 3873, 1999.
〔2〕 Bhattacharyya, K. , Volk, W. , Brown, D. , Ayala, J. and Grenon, B.J., “Investigation of Reticle Defect Formation at DUV
Lithography”, Proceedings of SPIE, Vol. 4889, 2002.
〔3〕 Wu, Banqiu and Kumar, Ajay ” Theoretical Study of Mask Haze Formation.”, Proceedings of SPIE Vol. 6792, 2008.
〔4〕 林陵杰，「介層洞優先雙層鑲嵌製程之研究」，南台科技大 學，碩士論文，民國 94 年。
〔5〕 Nii ,H., Kinoshita ,H., Watanabe, T., Matsuo, Y. and Sugie, Y.,”
Studies on EUV mask cleaning by dry and wet processes”, Proceedings of SPIE Vol. 6792, 2008.
〔6〕 Shimada,S. , Kanda, N. , Takahashi, N. , Nakajima, H. , Tanaka, H. , Ishii, H. , Shoji,Y. , Otsuki, M. , Naito, A. and Hayashi, N.
“A new model of haze generation and storage-life-time estimation for mask”, BACUS NEWS, Vol.23, issue 4,2007.
〔7〕 Shiao; Chia-Hwa , Tsai,Chien-Chung , Hsu;T. , Tuan;S., Chang;D. , Chen; R. , Hsieh, F.” Evaluation, Reduction and Monitoring of Progressive Defects on 193nm Reticles for Low-k1 Process”, Proceedings of SPIE Vol.5446, 2004.
〔8〕 Han, Sung-Jae , Kim, Bo-Hye , Park,Jin-Hong , Kim,
Yong-Hoon , Choi,Seong-Woon , Han,Woo-Sung,” The Study on Causes and Control Methods of Haze Contamination”, Proceedings of SPIE Vol.5645, 2005.
〔9〕 Ishii,H. , Tobita,A. , Shoji,Y. , Tanaka,,H. , Naito,A. and
Sang-Soo,” Haze generation effect by pellicle and packing box on photomask”, Proceedings of SPIE Vol.6730, 2007.
〔11〕 Jeong, Woo-Gun , Park, Dong-Il , Park, Eui-Sang ,
Cho,Young-Woong , Choi, Se-Jong , Kwon, Hyuk-Joo , Kim, Jin-Min , Choi, Sang-Soo” A Comparative Evaluation of Mask Cleaning Performance”, Proceedings of SPIE Vol. 5256, 2003.
〔12〕 張和裕，「半導體晶圓的清潔劑」，2009。
〔13〕 Graham, Michael , McDonald, Andrew ” Photomask cleaning process improvement to minimize ArF haze”, Proceedings of SPIE Vol.6792, 2008.
〔14〕 Ryu, Jin Ho , Lee, Dong Wook , Ryu, Ji Sun , Kim, Sang Pyo and Han, Oscar ” Novel cleaning techniques to achieve defect-free photomasks for sub-65nm nodes”, Proceedings of SPIE Vol.6349, 2006.
〔15〕 Hitoshi Handa, Masumi Takahashi, and Hisatsugu Shirai,”
Study of reticle cleaning process for 130nm lithography and beyond”, Proceedings of SPIE Vol. 4409, 2001.
〔16〕 Chovino, Christian and Dieu, Laurent” UV Light with Oxygen treatment of Phase shift photoblank for Phase and Transmission control. Applicable to MxSi(1-x)OyN(y-1)type”, Proceedings of SPIE Vol.5130,2003.
〔17〕 Lee, Dong Wook , Jung, Ho Yong , Kim, Mun Sik , Lee, Jun Sik , Choi,Yong Kyoo , Han, Oscar ” Effect of UV/O3treatment on mask surface to reducing sulfuric residue ions”, Proceedings of SPIE Vol.5567, 2004.
〔18〕 Eschbach, Florence , Tanzil, Daniel , Kovalchick, Mike , Dietze, Uwe , Liu, Min , Xu, Fei ” Improving photomask surface
properties through a combination of dry and wet cleaning steps”, Proceedings of SPIE Vol.5446, 2004.
〔19〕 Osbornea, Steve , Takahashia,Hidekazu , Wostera, Eric ” Mask Cleaning Strategies — A Continuous Ion Removal Concept”, Proceedings of SPIE Vol.6283, 2006.
〔20〕 Nagamura,Y. , Usui, H. , Yoshioka, N. and Morimoto, H. ” High performance photomask deaning process using electrolyzed water”, Proceedings of SPIE Vol.3412, 1998.
〔21〕 Chovino, Christian , Helbig, Stefan , Haschke, Petr , Saule, Werner ” Investigation of Sulfate Free Clean Processes for Next Generation Lithography”, Proceedings of SPIE Vol.5992, 2005.
〔22〕 Osborne, Steve , Nanninga, Matthias , Takahashi, Hidekazu , Woster, Eric ” Mask Cleaning Strategies—Haze Elimination”, Proceedings of SPIE Vol.5992, 2005.
〔23〕 Osborne, Steve , Nanninga, Matthias , Takahashi, Hidekazu , Woster, Eric , Kanda, Carl ” Mask Cleaning Strategies—Particle Elimination with Minimal Surface Damage”, Proceedings of SPIE Vol.5992, 2005.
〔24〕 Anzai, Shingo , Takagi, Noriaki , Kamiyama, Tomoaki ,
Kawaguchi, Naotoshi , Kuwajima, Tsuneaki , Nakatsub, Makito , Hasegawa, Shin-ichi ” Sulfate-free photomask cleaning
technology”, Proceedings of SPIE Vol.6283, 2006.
〔25〕 Perissinotti, Francesca , Sartelli, Luca , Cassago, Davide , Miyashita, Hiroyuki ” Full sulfate-free process: joint
achievement of minimal residual ions and yield improvement.”, Proceedings of SPIE Vol.6730, 2007.
〔26〕 Singh, Sherjang , Helbig, Stefan , Dress, Peter , Dietze, Uwe ” Study on surface integrity in photomask resist strip and final cleaning processes”, Proceedings of SPIE Vol.7379, 2009.
〔27〕 Han,Sung-Jae , Yu, Sang-Yong , Sung, Moon-Gyu , Kim, Yong-Hoon , Yoon, Hee-Sun , Sohn, Jung-Mm” The Study on Characteristics and Control of Haze Contamination induced by Photochemical Reaction”, Proceedings of SPIE Vol.5130, 2003.
〔28〕 Chen, Gim , Reyes, Julio , Wood, James , Kashkoush, Ismail , Dieu, Laurent , Novak, Richard ” Immersion System Process Optimization for 248nm and 193nm Photomasks – Binary and EAPSM”, Proceedings of SPIE Vol.5256, 2003.
〔31〕 Eschbach, F. , Selassie, D. , Sanchez, P. , Tanzil, D. , Tolani, V. , Toofan, M. , Liu, H. , Greenebaum, B. , Murray, M. , Villacorta, R. “ArF lithography reticle crystal growth contributing factors”, Proceedings of SPIE Vol. 5567, 2004.
附 錄 一 UV/O3 法數據比較【離子殘留率】
33
附 錄 二 UV/O3 法數據比較【光學性質】
附 錄 三 電解水法數據比較【離子殘留率】
清洗條件 傳統法
傳統法 +DIO3+DIH
2 M/S+DI rinse+DUV
傳統法 +DIO3+DIH2
M/S+CO2 purge+DUV
DIO3 DIH2
high conc DIO3+SPI
N
硫離子殘留率 1 1.4 0.96 0.35 0.1 0
銨離子殘留率 1 0.39 0.3 0
*資料來源 DNP[25] DNP[25] Toppan[21] Toppan[21] Toppan[24]
35
附 錄 四 電解水法數據比較【光學性質】
清洗條件 傳統法 DIH2 DIH2+NH4OH APM DIH2 SC1 DIO3 DIO3+DIH
2 DIO3+SC1
DIO3
(Normalize) 1 1 0.78 1 0.19 0.065 0.023
穿透度
(Normalize) 1 0.01 0.1 1 0.27 0.29 0.08 0.01 0.15 0.06 0.012
*資料來源 Wacom[20] Wacom[20] Wacom[20] Toppan[21] Toppan[21] Toppan[21] Toppan[21] Toppan[21] SL[22] SL[23]
清洗條件
high conc DIO3+SPI
NH4OH DIO3+SC1 DIO3 APM SOM SPM
+HT SC1
25C dilute NH4OH +M/S+SP
IN 相移角度
(Normalize) 0.05 0.34 0.17 0.39 0.7 0.39 1.21 0.7 0.62 0.56
穿透度
(Normalize) 0.002 0.03 0.024 0.036 0.02 0.03
*資料來源 Toppan[24] DNP[25] DNP[25] Samsung[27] DuPont[28] DuPont[28] DuPont[28] DuPont[28] DuPont[29] DuPont[29]