由於奈米壓印技術近年來大量取代傳統黃光微影製程，使得製作結構上更加快速且多樣化，並能製作許多含有高分子組成之結構。然而，高分子材料會受到製程溫度、配方不同、材料產生不同鍵結或形變等影響，在數值模擬其輻射性質時，成為相當棘手的問題，進而無法有效率的設計光學元件或其他應用。因此本研究利用數值模擬與實驗量測的方式，探討數個一維微米級單式光柵與複式光柵的紅外線穿透性質。而這些具有不同結構尺寸的樣本是利用接觸轉印與金屬植入式顯影技術所製作，在中摻雜濃度矽(8.2×1016cm-3)基板上結合金屬(Au及Cr)及高分子(PMMA)製作一維狹縫結構。在實驗量測上，利用傅立葉轉換紅外線光譜儀(FT-IR)針對兩個線性極化方向量測樣本在中紅外波段(2.5 um - 25 um)之正向入射穿透率。在數值模擬上，利用嚴格耦合波理論(RCWA)來計算其輻射性質並與實驗量測結果做對照。其特殊頻譜現象將會在本文中介紹，並解釋其原因。此外，本文也針對PMMA與高摻雜濃度矽在紅外光波段之光學常數作一探討，並成功獲得其光學常數。

Compared to traditional photolithography, the nano-imprinting method is superior for the reduction of the processing time and the capabilities of making various structures, also those with polymers. However, due to the effects of processing temperature, composing of materials, interatomic bondings, and deformation, to model the radiative properties of structures with polymers would be challengeable. As a result, to design optical devices and other applications is difficult. Hence, this work investigated the infrared transmittance through several microscale one-dimensional simple/complex gratings both experimentally and theoretically. These samples of different profiles are composed of metals (Au and Cr), a polymer (PMMA), and a medium-doped (8.2×1016cm-3) Si substrate and fabricated through contact-transferred and mask-embedded lithography method. The normal transmittances were measured at two linear polarizations in the mid-infrared region (2.5 um to 25 um) with a Fourier Transform Infrared (FT-IR) spectrometer. The measured transmittance spectra are compared with numerical results from the rigorous coupled-wave analysis (RCWA). Unique spectrum of samples were demonstrated and explained with physical mechanisms. Moreover, this work also investigated the optical constants of PMMA and highly-doped Si in the infrared region.

1. Chou, S. Y., Krauss, P. R., and Renstrom, P. J., 1995, “Imprint of Sub-25 nm Vias and Trenches in Polymers,” Appl. Phys. Lett., 67, pp. 3114-3116.
2. Chou, S. Y., Krauss, P. R., and Renstrom, P. J., 1996, “Imprint Lithography with 25-Nanometer Resolution,” Science, 272, pp. 85-87.
3. Guo, L., Krauss, P. R., and Chou, S. Y., 1997, “Nanoscale Silicon Field Effect Transistors Fabricated Using Imprint Lithography,” Appl. Phys. Lett., 71, pp. 1881-1183.
4. Zhang, W., and Chou, S. Y., 2003, “Fabrication of 60-nm Transistors on 4-in. Wafer Using Nanoimprint at all Lithography Levels,” Appl. Phys. Lett., 83, pp. 1632-1634.
5. Stewart, M. D., Johnson, S. C., Sreenivasan, S. V., Resnick, D. J., and Willson C. G., 2005, “Nanofabrication with Step and Flash Imprint Lithography,” J. Microlith. Microfab. Microsyst., 4, pp. 011002-1/6.
6. Colburn, M., Johnson, S., Stewart, M., Damle, S., Bailey, T., Choi, B., Wedlake, M., Michaelson, T., Sreenivasan, S. V., Ekerdt, J., and Willson, C. G., 1999, “Step and Flash Imprint Lithography: A New Approach to High-Resolution Patterning,” Proc. SPIE, 3676, pp. 379–389.
7. Zhao, X. M., Xia, Y., and Whitesides, G. M., 1997, “Soft Lithography Methods for Nano-Fabrication,” J. Mater. Chem., 7, pp. 1069-1074.
8. Xia, Y., and Whitesides, G. M., 1998, “Soft Lithography,” Annu. Rev. Mater. Sci., 28, pp. 153-184.
9. Mcclelland, G. M., Hart, M. W., Rettner, C. T., Best, M. E., Carter, K. R., and Terris, B. D., 2002, “Nanoscale Patterning of Magnetic Islands by Imprint Lithography Using a Flexible Mold,” Appl. Phys. Lett., 81, pp. 1483-1485.
10. Kim, S. H., Lee, K. D., Kim, J. Y., Kwon, M. K., and Park, S. J., 2007, “Fabrication of Photonic Crystal Structures on Light Emitting Diodes by Nanoimprint Lithography,” Nanotechnology, 18, pp. 055306.
11. Cho, H. K., Jang, J., Choi, J. H., Choi, J., Kim, J., Lee, S. J., Lee, B., Choe, Y. H., Lee, K. D., Kim, S. H., Lee, K., Kim, S. K., and Lee, Y. H., 2006, “Light Extraction Enhancement from Nanoimprinted Photonic Crystal GaN-Based Blue Lightemitting Diodes,” Opt. Express, 14, pp. 8654-8660.
12. Austina, M. D., and Chou, S. Y., 2002, “Fabrication of 70 nm Channel Length Polymer Organic Thin-Film Transistors Using Nanoimprint Lithography,” Appl. Phys. Lett., 81, pp. 4431-4433
13. Han, K. S., Shin, J. H., and Lee, H., 2010, “Enhanced Transmittance of Glass Plates for Solar Cells Using Nano-Imprint Lithography,” Solar Energy Materials & Solar Cells, 94, pp. 583-587.
14. Hera, H. J., Kima, J. M., Kanga, C. J., and Kim, Y. S., 2008, “Hybrid Photovoltaic Cell with Well-Ordered Nanoporous Titania–P3HT by Nanoimprinting Lithography,” J. Phys. Chem. Solids, 69, pp. 1301-1304.
15. Basu, S., Chen, Y.-B., and Zhang, Z. M., 2007, “Microscale Radiation in Thermophotovoltaic Devices—A Review,” Int. J. Energy Res., 31, pp. 689-716.
16. Kim, S. H., Park, J.-D., and Lee, K.-D, 2006, “Fabrication of a Nano-Wire Grid Polarizer for Brightness Enhancement in Liquid Crystal Display,” Nanotechnology, 17, pp. 4436-4438.
17. Yeh, P., 1981, “Generalized Modal for Wire Grid Polarizers,” Proc. SPIE, 307, pp. 13-21.
18. Ye, Y., Zhou, Y., and Chen, L., 2009, “Color Filter Based on a Two-Dimensional Submicrometer Metal Grating,” Appl. Opt., 48, pp.5035-5039.
19. Foresi, J. S., Villeneuve, P. R., Ferrera, J., Thoen, E. R., Steinmeyer, G., Fan, S., Joannopoulos, J. D., Kimerling, L. C., Smith, H. I.,and Ippen, E. P., 1997, “Photonic-bandgap Microcavities in Optical Waveguides,” Nature, 390, pp. 143-145.
20. Chen, Y.-B., Lee, B. J., and Zhang, Z. M., 2008, “Infrared Radiative Properties of Submicron Metallic Slit Arrays,” ASME J. Heat Transfer, 130, pp. 082404-1/8.
21. Crouse, D., and Keshavareddy P., 2007, “Polarization Independent Enhanced Optical Transmission in One-Dimensional Gratings and Device Applications,” Opt. Express, 15, pp. 1415-1427.
22. Astilean, S., Lalanne, P., and Palamaru, M., 2000, “Light Transmission through Metallic Channels Much Smaller Than the Wavelength,” Opt. Commun., 175, pp. 265-273.
23. Chan, H. B., Marcet, Z., Woo, K., Tanner, D. B., Bower, J. E., Cirelli, R. A., Ferry, E., Klemens, F., Miner, J., Pai, C. S., and Taylor, J. A., 2006, “Optical Transmission Through Double-Layer Metallic Subwavelength Slit arrays,” Opt. Express, 31, pp. 516-518.
24. Wang, J., Schablitsky, S., Yu, Z., Wu, W and Chou, S. Y., 1999, “Fabrication of a New Broadband Waveguide Polarizer with a Double-Layer 190 nm Period Metal-Gratings Using Nanoimprint Lithography,” J. Vac. Sci., Technol. B, 17, pp. 2957-2960.
25. Yu, Z., Deshpande, P., Wu, W., Wang, J., and Chou, S. Y., 2000, “Reflective Polarizer Based on a Stacked Double-Layer Subwavelength Metal Grating Structure Fabricated Using Nanoimprint Lithography,” Appl. Phys. Lett., 77, pp. 927-929.
26. Wang, J., Sun, X., Chen, L., and Chou, S. Y., 1999, “Direct Nanoimprint of Submicron Organic Light-Emitting Structures,” Appl. Phys. Lett., 75, pp. 2767-2769.
27. Palik, E. D., 1998, Handbook of Optical Constants of Solids, Academic, SanDiego, CA, Vols. I and II.
28. Yeh, P., 1998, Optical Waves in Layered Media, Wiley, New York.
29. Zhang, Z. M., 2007, Nano/Microscale Heat Transfer, McGraw-Hill, New York.
30. Poruba, A., Fejfar, A., Remes, Z., Springer, J., Vanecek, M., Kocka, J., Meier, J., Torres, P., and Shah, A., 2000, “Optical Absorption and Light scattering in Microcrystalline Silicon Thin Films and Solar Cells,” J. Appl. Phys., 88, pp. 148-160.
31. Walheim, S., Schaffer, E., Mlynek, J., and Steiner, U., 1999, “Nanophase-Separated Polymer Films as High-Performance Antireflection Coatings,” Science, 283, pp. 520-522.
32. Chen, Y.-B., and Zhang, Z. M., and Timans, P. J., 2007, “Radiative Properties of Patterned Wafers with Nanoscale Linewidth,” J. Heat Transfer, 129, pp. 79-90.
33. Moharam, M. G., Grann, E. B., Pommet, D. A., and Gaylord, T. K., 1995, “Formulation for Stable and Efficient Implementation of the Rigorous Coupled-Wave Analysis of Binary Gratings,” J. Opt. Soc. Am. A., 12, pp. 1068-1076.
34. Incropera, F. P., and DeWitt, D. P., 2002, Fundamentals of Heat and Mass Transfer, 5th ed., J. Wiley, New York.
35. Griffiths, P. R., and De Haseth, J. A., 1986, Fourier Transform Infrared Spectrometry, Wiley, New York.
36. Welch, P. D, 1967, “The Use of Fast Fourier Transform for the Estimation of Power Spectra: A Method Based on Time Averaging Over Short, Modified Periodograms,” IEEE Trans. Audio and Electroacoust, 15, pp. 70-73.
37. Bell, R. J., 1972, Introductory Fourier Transform Spectroscopy, Academic Press, New York.
38. Kaplan, S. G., Hanssen, L. M., and Datla, R. U., 1997, “Testing the Radiometric Accuracy of Fourier Transform Infrared Transmittance Measurements,” Appl. Opt., 36, pp. 8896-8908.
39. Flik, M. I., and Zhang, Z. M., 1992, “Influence of Nonequivalent Detector Responsivity on FT-IR Photometric Accuracy,” J. Quant. Spectrosc. Radiat. Transf., 47, pp. 293-303.
40. Born, M., and Wolf, E., 1975, Principles of Optics, Pergamon Press, Oxford, United Kingdom.
41. Birch, R. J., and Clarke, F. J. J., 1998, “Interreflection Errors in Fourier Transform Spectroscopy: A Preliminary Appraisal,” Anal. Chim. Acta., 380, pp. 369-378.
42. Mertz, L., 1965, Transformations in Optics, Wiley, New York.
43. Kim, D., 2005, “Polarization Characteristics of a Wire-Grid Polarizer in a Rotating Platform,” Appl. Opt., 44, pp. 1366-1371.
44. Neuringer, L. J., and Milward, R. C., 1967, “Heavily Doped Silicon as a Low Temperature Transmission Filter for the Far Infrared,” Appl. Opt., 6, pp. 978-979.
45. Madou, M., 1997, Fundamentals of Microfabrication. CRC Press, New York.
46. Ehsani, H., Bhat, I., Borrego, J., Gutmann, R., Brown, E., Dziendziel, R., Freeman, M., and Choudhury, N., 1997, “Optical Properties of Degenerately Doped Silicon Films for Applications in Thermophotovoltaic Systems,” J. Appl. Phys., 81, pp. 432-439..
47. Chen, Y. B., 2009, “Development of Mid-Infrared Surface Plasmon Resonance-Based Sensors with Highly-Doped Silicon for Biomedical and Chemical Applications,” Opt. Express, 17, pp. 3130-3140.
48. Engstrom, H., 1980, “Infrared Reflectivity and Transmissivity if Boron Implanted, Laser-Annealed Silicon,” J. Appl. Phys., 51, pp. 5245-5249.
49. Barta, E., and Lux, G., 1983, “Calculated and Measured Infrared Reflectivity of Diffused Implanted p-Type Silicon Layers,” J. Phys. D, 16, pp. 1543-1553.
50. Xiao, H., 2001, Introduction to Semiconductor Manufacturing Technology, NJ :Prentice Hall, Upper Saddle River.
51. Marquier, F., Joulain, K., Mulet, J-P., Carminati, R., and Greffet, J.-J, 2004, “Engineering Infrared Emission Properties of Silicon in the Near Field and the Far Field,” Opt. Commun., 237, pp. 379-388.
52. Basu, S., Lee, B. J., amd Zhang, Z. M., 2010, “Infrared Radiative Properties of Heavily Doped Silicon at Room Temperature,” J. Heat Transf.-Trans. ASME, 132, pp. 023301-1/8.
53. Lee, Y. C., and Chiu, C. Y., 2008, “Micro-/Nano-Lithography Based on the Contact Transfer of Thin Film and mask Embedded Etching,” J. Micromech. Microeng., 18, pp. 075013.
54. Jung, G. Y., Li, Z., Wu, W., Chen, Y., Olynick, D. L., Wang, S. H., Tong, W. M., and Willams, R. S., 2005, “Vapor-Phase Self-Assembled Monolayer for Improved Mold Release in Nanoimprint Lithography,” Langmuir, 21, pp. 1158-1161.
55. Chen, Y. B. and Zhang, Z. M., 2007, “Design of Tungsten Complex Gratings for Thermophotovoltaic Radiators,” Opt. Commun., 269(2), pp.411-417.
56. Siegel, R., and Howell, J. R., 2002, Thermal Radiation Heat Transfer, 4th ed., Taylor & Francis, New York.
57. Ryoo, K., Kim, H. R., Koh, J. S., Seo, G., and Lee, J. H., 1992, “Fine Structure of Oxygen Absorption Bands in Si at Low Temperature,” J. Appl. Phys., 72, pp. 5393-5396.
58. Zhao, Y. G., Lu, W. K., Ma, Y., Kim, S. S., and Ho, S. T., 2000, “Polymer Waveguides Useful Over a Very Wide Wavelength Range from the Ultraviolet to Infrared,” J. Appl. Phys. Lett., 77 (19), pp. 2961-2963.
59. Kim, Y., 2000, “Physical, Chemical and Optical Properties of Aqueous L-arginine phosphate (LAP) Solution,” J. Mater. Sci., 35, pp. 873–880.
60. Khodier, S. A., 2002, “Refractive Index of Standard Oils as a Function of Wavelength and Temperature,” Optics & Laser Technology, 34, pp. 125–128.
61. Saito, M., Gojo, T., Kato, Y., and Miyagi, M., 1995, “Optical Constants of Polymer Coatings in the Infrared,” Infrared Physics & Technology, 36, pp. 1125-1129.
62. Khashan, M. A., and Nassif, A. Y., 2001, “Dispersion of the Optical Constants of Quartz and Polymethyl Methacrylate Glass in a Wide Spectral Range: 0.2-3 μm,” Opt. Commun., 188, pp. 129-139.
63. Werner, G., 1988, “Overtone Absorption in Macromolecules for Polymer Optical Fibers,” Macromolecular Chemistry and Physics, 189, pp. 2861-2874.
64. Shin, H. S., Lee, H., Jun, C. H., Jung, Y. M., and Kim, S. B, 2005, “Transition Temperatures and Molecular Structures of Poly(methyl methacrylate) Thin films by Principal Component Analysis: Comparison of Isotactic and Syndiotactic Poly(methyl methacrylate),” Vibrational Spectroscopy, 37, pp. 69-76.
65. Lee, C. C., Hsu, H. C., and Jaing, C. C., 1997, “Optical Coatings on Polymethyl methacrylate and Polycarbonate,” Thin solid films, 295, pp. 122-124.
66. Hessel, A., and Oliner, A. A., 1965, “A New Theory of Wood’s Anomalies on Optical Gratings,” Appl. Opt., 4, pp. 1275-1297.
67. Modest, M. F., 2003, Radiative Heat Transfer, McGraw-Hill Inc., New York.
68. Ordal, M. A., Long, L. L., Bell, R. J., Bell, S. E, Bell, R. R., Alexander, R. W., Jr., and C. A. Ward, 1985, “Optical Properties of the Metals Al, Co, Cu, Au, Fe, Pb, Ni, Pd, Pt, Ag, Ti, and W in the Infrared and Far Infrared,” Appl. Opt., 22, pp. 1099-1120.
69. Lee, B. J., Chen, Y. B, and Zhang, Z. M., 2008, “Transmission Enhancement Through Nanoscale Metallic Slit Arrays from the Visible to Mid-Infrared,” J. Comput. Theor. Nanosci., 5, pp. 1-13.