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2 奈 年度 精 行度 行 精 類 兩 (dual-stage control) 行 奈 精 量 量 量 量 理 CCD 數 奈 力 奈 奈 I

3 The aim of this project is to design and construct a nano-imprint lithography platform with precision alignment capability. In this year, the imprint platform was designed and verified and the overlay alignment process was also developed and verified with simulation and simple experiments. There are two major alignment issues on nano-imprint system. One is the parallel control of mold and wafer, the other is the overlay control between the mold and wafer. With regard to the parallel control, a hydro-pressure system will be applied to the mold, and when equal pressure contacts with the mask, the parallelism is naturally achieved, thus eliminating 2 degrees of alignment freedom. To improve the overlay control of the nano-imprint system, we are going to integrate diffractive laser encoder previously developed by our research team. The laser encoder takes 1 order diffractive beam form grating ruler into interference, and could achieve sub angstrom resolution and better than 10nm accuracy. The gratings are going to be directly fabricated onto the mold and the wafer, and with the special designed diffractive laser encoder optical head with absolutely positioning capability to offer sub-100nm overlay control precision. Dual-stage control strategy will be applied on the precision overlay control system. In the first stage, X-Y stage provides rough alignment on micron scale with traditional alignment mark and white light microscopy techniques. In the second stage, feedback control on piezoelectric actuators in conjunction with the special design diffractive laser encoder will offer nano-scale precision positioning. With joint efforts of other sub-projects, we are going to build a complete nano-imprint system with nano-scale overlay control capability in this project. Keywordsnano-imprintlithographyoverlap controlprecision alignmentdiffractive laser encoder II

4 ITRS (International Technology Roadmap for Semiconductors) Roadmap 100 奈 (DRAM half-pitch linewidth) 2016 年 10 奈 奈 100 奈 10 奈 (lithography) 臨 150 奈 50 奈 臨 奈 (nano-imprint) 了 CD(critical dimension) 10 奈 路 論 奈 10 奈 奈 精度 奈 利奈 精 都 雷 (distance measurement interferometer) 都 年 雷 易 1 奈 度 (resolution) 精度 (accuracy) 雷 度 雷 路 率 量 abbecosine 雷 精度 10 奈 100 奈 CD 量 10 奈 說 30 年 雷 量 零 都 都 100 奈 量 不 例 (overlay control) 2005 年 了 量 領 行 雷 精度 離 10nm100 nm 精度 度 六 奈 了 度 X tiltingy tiltingz positionxyrotation 3

5 度 奈 都 利 理 說 行 年來 利 量 亮度 度 不 量 度 離 了 更 2000 年 WhiteWood 奈 利 精 4.1 量 1.6 利 兩 行 離 離 離 量 離 量 理 路 nm 雷 行 路 兩 (CCD, charge coupled device) 濾 離拉 濾 DAQ 數 4.2 奈 不 奈 省 了 度 精 行度 精度 更 參 了 料 ( 4.2) 藍 力不 不 ( 4.3) 4

6 4.1 路 4.2 料 4.3 了 不 力 力 力 (soft contact) 4.3 5

7 4.3 論 5.1 行 G-Solver OptiFDTD 2000 年 D.L. White O. L. Wood G-Solver OptiFDTD 來 G-Solver 來 論 離 率 5.1 GSolver 5.2 不 GSolver 6

8 5.1 Gsolver 5.2 了 度 GSolver GSolver Pitch1.6µmPhase grating 度 172 nm (SiO) 度 111 nm 度 0.8um 率 論 度 不易 狀 不 裂 北 1um 150nm 度 易 不 裂 度 111nm 兩 離 量 兩 率 類 爲了 兩 利 GSolver 5.3 理 um 率 藍 零 率 數 率 率 數 率 藍綠 率 數 零 綠 率 1.6um 數 數 了 率 來 7

9 利 來 了 率 離 離 率 了 參 5.4 0nm 100nm 料 率 率 離 90nm 離 離 兩 若 量 離 90nm 若 來 5.3 量 5.4 離 率 8

10 5.2 理論 兩 離 行 度不 爲 理論 奈 雷 兩 不 2um 度 200nm 1.6um 度 300nm 爲 度 爲 兩 滑 利 NI Vision Assistant 理 IMAQ 來 行 亮 ( 行 ) 度 利 量 NI Vision Assistant 5.6 量 um 零 藍 9

11 來 1 ripple 3.5um 4um 來 亂 度 異 流 Z 度 Z 輪 ( 5.7)Z 離若 來 料

12 5.7 率 5.3 論 濾 離 (<1um)(~5um) 不 量 不 率 離 都 勒 1.6µm 了 度 度 行 率 來 行 量 精 度 理 行 來 理論 離 11

13 若 立 料 利 離 了 行 3D 奈 行 參 1. Lloyd R. Harriott, Limits of Lithography, Proceeding of the IEEE, vol.89, NO.3, March 2001, pp R. A. Lawes, Future trends in high-resolution lithography, Applied Surface Science, , 2000, pp Rau et al., Short-noise and Edge Roughness Effects in Resists Patterned at 10nm Exposure, Journal of Vacuum Science & Technology B, vol. 16, 1998, pp Stephen Y. Chou, Peter R. Krauss, and Preston J. Renstorm, Imprint of sub-25nm vias and trends in polymers, Applied Physics Letters, vol. 67, 1995, pp D L White, O R Wood, Novel alignment system for imprint lithography, Journal of Vacuum Science & Technology B, vol. 18, 2000, pp C. S. Su and Y. S. Ku, An Ion Source for Low Energy Ion Scattering Spectrometry, Vacuum, vol. 40, 2000, pp Nyyssonen, D., Theory of optical edge detection and imaging of thick layers, J. Opt. Soc. Am., 72, pp , Kirk, C. P., and Nyyssonen, D., Modeling the Optical Microscope Images of Thick Layers for the Purpose of Linewidth Measurement, SPIE 538, pp , Yuan, C., and Strojwas, A. J., Modeling the Optical Alignment and Metrology Schemes Used in Integrated Circuit Manufacturing, SPIE 1264, pp , Seligson, J. L. et al., Overlay metrology simulations - Analytical and experimental validations, Proceedings of SPIE Vol. 5038, pp (2003). 11. Seligson, J. L. et al., Overlay Metrology Simulations, Proceedings of SPIE Vol. 4689, pp (2002). 12. T. K. Gaylord, Analysis and Applications of optical diffraction by gratings, Proceedings of the IEEE 73, pp , S. Astilean, P. Lalanne, and M. Palamaru, Light transmission through metallic channels much smaller than the wavelength Opt. Commun 175, pp ,