摘要

近年來，表面電漿在奈米光學領域裡是個相當熱門的題目。此篇論文主要研究紅外線波段的入射光與具有特定結構的金屬表面之間的耦合機制。
具有T型陣列的結構，不僅僅是利用存在銀與二氧化矽表面之間的電漿共振，還藉由中間的銀達到更好的侷域表面電漿特性。
由於此特別的結構，在此篇論文裡我們也會介紹奈米圖形產生系統裡面的對準系統。而此對準系統的誤差可以小於50nm。
此結構的所有特性也會藉由RCWA模擬方式表達出來。利用此結構在實驗方面我們也成功的得到可調變式的侷域表面電漿模態。

Abstract

In recent years, surface plasmon is very popular topics in the nano optics. The thesis is major to study the feature which the coupling of metal film with specific periodic structure and incident light with infrared wavelength.
The structure with T-shaped array not only employs the coupling of two SPP modes at interfaces Ag/SiO2 but also use the silver bridge. Depend on the silver bridge we can get better characteristic for localizing surface plasmon polariton.
Because of the specific structures we will also demonstrate the alignment technique in nanometer pattern generation system. The accuracy of alignment can be smaller than 50nm.
In simulation the other characteristics also been developed by using the theory of RCWA. Finally in the experiment we successfully obtain a tunable narrow localized surface plasmon (LSPP) mode by using the structure.

Abstract (in Chinese)
Abstract (in English)
Acknowledgements
List of Figures
List of Tables

Chapter 1 Introduction

1.1 Introduction to Surface Plasmon Polaritons
1.2 Motivation

Chapter 2 Fundamentals of Surface Plasmon

2.1 The Condition of Exciting Surface Plasmon Polaritons
2.2 Exciting Surface Plasmon Polaritons through Metal Film with Periodic Structures
2.3 Dielectric Function of Metal
Chapter 3 Fabrication

3.1 Electron Beam Lithography
3.1.1 Introduction
3.1.2 Nanometer Pattern Generation System (NPGS)
3.1.3 Alignment System
3.2 Film Deposition
3.2.1 Electron Gun Evaporators
3.2.2 RF Sputter
3.3 Etching
3.3.1 Reactive Ion Etching
3.3.2 Inductively Coupled Plasma Etching
3.4 The Process of The T-Shaped Array Structure
3.5 The Process of The Two-Dimensional Triangular Lattice Holes Array Metallic Structures

Chapter 4 Localized Surface Plasmon Mode of T-shaped Array Structure

4.1 Introduction to T-Shaped Array Structure
4.2 Simulation
4.2.1 Index of Materials
4.2.2 Different Variables
4.3 Measurements and Analysis

Chapter 5 Conclusions

Reference

List of Figures

Figure 1-1: The scattering spectra correspond to silver nanoparticle with different shapes. (P.2)
Figure 1-2: (a) The geometry of plasmonic multilayer structure [23]. (b) The geometry of T-shaped array structure. (c) Absorbance spectrum of plasmonic multilayer structure. (d) Absorbance spectrum of T-shaped array structure. (P.5)
Figure 2-1: The schematic of a beam incident into the interface dielectric/metal. (P.7)
Figure 2-2: Dispersion relations of SPPs and incident light. (P.10)
Figure 2-3: The schematic of a beam incident into the metal film with one-dimensional grating. (P.11)
Figure 2-4: The schematic of periodic square lattice structure. (P.13)
Figure 2-5: Figure 2-5 The schematic of periodic triangular lattice structure. (P.14)
Figure 3-1: The trajectory of different accelerated voltage of electron (a) 10 keV (b) 25 keV (c) 50 keV [19] (P.20)
Figure 3-2: Thickness versus spin speed and different ratio of photo resist [20]. (P.22)
Figure 3-3: The comparison of different ratio of developer [20]. (P.23)
Figure 3-4: The standard flow chart of electron beam lithography. (P.25)
Figure 3-5: The alignment divides into four parts. (P.28)
Figure 3-6: The design pattern of step 1 for alignment. (P.29)
Figure 3-7: The design pattern of step 2 for alignment. (P.29)
Figure 3-8: The design pattern of step 3 for alignment. (P.30)
Figure 3-9: The SEM image at cross section. The bright part is SiO2, and the dark part is Si. The thickness of SiO2 is about 100nm. (P.32)
Figure 3-10: The 45° angle SEM image of deposited silver film on PMMA with 1-D periodic grating. (P.32)
Figure 3-11: The thickness of the silica is about 50nm. (P.34)
Figure 3-12: The top view of SEM image after sputter silica film on the top of silver. (P.34)
Figure 3-13: The SEM image which has Re-deposition phenomenon. (P.36)
Figure 3-14: The SEM image after etching 100nm silver film and removing the resist. (P.37)
Figure 3-15: The SEM image at cross section. (P.39)
Figure 3-16: The SEM image at cross section of sample A. (P.40)
Figure 3-17: The SEM image at cross section of sample B. (P.41)
Figure 3-18: The SEM image at cross section of sample C. (P.41)
Figure 3-19: The SEM image of the T-shaped array structure after ICP etching silica. (P.42)
Figure 3-20: The flow chart of first part for T-shaped array structure (a) The thickness of SiO2 is 50nm, and the thickness of Ag is 100nm. (b) The thickness of PMMA is 300nm. (c) The lattice constant is 3000nm, and WT is 800nm. (d) The completion of first part. (P.44)
Figure 3-21: The flow chart of second layer of T-shaped array structure (a) Prepare to second electron lithography. (b) The range of WAg is 1100nm to 2000nm. (c) The thickness of Ag is 100nm. (d) The completion of T-shaped array structure. (P.46)
Figure 3-22: The 45° angle SEM image of T-shaped array structure. (P.47)
Figure 3-23: The cross-sectional SEM image of T-shaped array structure. (P.47)
Figure 3-24: The flow chart of fabricating 2-D triangular lattice holes array metallic structures (a) The 100nm silver film was deposited on top of SiO2 (b) The patterns was designed on PMMA (c) The lattice constant is about 400nm to 600nm. (P.49)


Figure 3-25: The top view of SEM image of 2-D triangular lattice holes array metallic structures. The actual area of the device size is bout 400μm2. (P.50)
Figure 3-26: The 45° angle SEM image of 2-D triangular lattice holes array metallic structures. (P.50)
Figure 4-1: The geometry of plasmonic multilayer structure [23]. (P.52)
Figure 4-2: Absorbance spectrum of plasmonic multilayer structure was simulated by RCWA. (a=3000nm, tAg1=100nm, tw=50nm, tAg2=100nm and WAg=1500nm.) (P.53)
Figure 4-3: The Hy2 distribution of plasmonic multilayer structure at (a) 0.21eV (b) 0.37eV (c) 0.55eV. (P.55)
Figure 4-4: The geometry of T-shaped array structure. (P.56)
Figure 4-5: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1400nm) (P.57)
Figure 4-6: Hy2 distribution at 0.35eV with an incident angle of 0°. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1400nm) (P.57)
Figure 4-7: Refractive index of silver. (a) real part (b) imaginary part (P.59)
Figure 4-8: Refractive index of SiO2. (a) real part (b) imaginary part (P.60)
Figure 4-9: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, WT=800nm, and WAg=1400nm) (P.61)
Figure 4-10: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, WT=800nm, and WAg=1600nm.) (P.62)
Figure 4-11: Resonant wavelength as a function of the width WAg. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, WT=800nm, and WAg=1100nm~1900nm.) (P.62)
Figure 4-12: Resonant wavelength as a function of the thickness tw. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=10~150nm, WT=800nm, and WAg=1500nm.) (P.64)
Figure 4-13: Resonant wavelength as a function of the cavity length Lc. [a=3000nm, tAg1=100nm, tAg2=100nm, tw=30nm (black dots) and 50nm (red dots), WT=800nm] (P.64)
Figure 4-14: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=10nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1600nm.) (P.65)
Figure 4-15: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=20nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1600nm.) (P.66)
Figure 4-16: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3000nm, tAg1=70nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1600nm.) (P.66)
Figure 4-17: The resonant wavelength as a function of the width tAg1. (P.67)
Figure 4-18: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=2500nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1500nm) (P.68)
Figure 4-19: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3200nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1500nm) (P.68)
Figure 4-20: Absorbance spectrum of T-shaped array structure was simulated by RCWA. (a=3500nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1500nm) (P.69)
Figure 4-21: The schematic of varying angle for measurement. (P.69)
Figure 4-22: Absorbance spectra for incident angle of 0. (a) WAg = 1300nm (b) WAg = 1540nm (c) WAg = 1910nm (P.71)
Figure 4-23: The comparisons of resonant wavelength between simulation and measurement. (P.72)
Figure 4-24: The absorbance spectra of WAg=1540nm with incident angle from 0° to 15°. (P.72)
Figure 4-25: Absorbance spectrum of T-shaped array structure was simulated by RCWA. The width WAg is not at the center and top of the WT. The inaccuracy of the location is 100nm corresponding to the center. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg=1500nm) (P.73)
Figure 4-26: The SEM image of WAg=1650nm. (P.74)
Figure 4-27: Absorbance spectra for incident angle of 0°. (a=3000nm, tAg1=100nm, tAg2=100nm, tw=50nm, wT=800nm, and WAg = 1650nm) (P.74)

List of Tables

Table 2-1: The data of plasma frequency and collision frequency for different metals. (P.17)
Table 3-1: N are the numbers of the alignment window [21]. (P.28)
Table 3-2: The recipe of sputtering silver on the silica substrate. (P.33)
Table 3-3: The recipe of etching the 100nm silver film. (P.36)
Table 3-4: The comparison between with RIE and ICP. (P.38)
Table 3-5: The recipe of etching silica. (P.39)
Table 3-6: The recipe of etching 50nm silica film. (P.42)

Reference

[1] R. W. Wood, “On a Remarkable Case of Uneven Distribution of Light in a Diffraction Grating Spectrum,” Proc. Phys. Soc. London. 18, 269-275 (1902)
[2] J. C. Maxwell Garnett, “Colours in Metal Glasses and in Metallic Films,” Philos. Trans. R. Soc. London. 203, 385-420 (1904)
[3] R.H. Ritchie, “Plasma Losses by Fast Electrons in Thin Films,” Phys. Rev. 106, 874-881 (1957)
[4] T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio, P. A. Wolff, “Extraordinary optical transmission through sub-wavelength hole arrays,” Nature. 391, 667-669 (1998)
[5] U. SchrÖter and D. Heitmann, “Grating couplers for surface plasmons excited on thin metal films in the Kretschmann-Raether configuration,” Phys. Rev. Lett. 60, 4992-4999 (1999)
[6] L. Salomon, F. Grillot, A. V. Zayats, and F. de Fornel, “Near-Field Distribution of Optical Transmission of Periodic Subwavelength Holes in a Metal Film,” Phys. Rev. Lett. 86, 1110-1113 (2001)
[7] J. J. Mock, M. Barbic, D. R. Smith, D. A. Schultz, and S. Schultz, “Shape effects in plasmon resonance of individual colloidal silver nanoparticles,” J. Chem. Phys. 116, 6755-6759 (2002)
[8] Tzyy-Jiann Wang and Chih-Wei Hsieh, “Phase interrogation of localized surface plasmon resonance biosensors based on electro-optic modulation,” Appl. Phys. Lett. 91, 113903 (2007).
[9] Sylvain Herminjard, Lorenzo Sirigu, Hans Peter Herzig, Eric Studemann, Andrea Crottini, Jean-Paul Pellaux et al., “Surface Plasmon Resonance sensor showing enhanced sensitivity for CO2 detection in the mid-infrared range,” Opt. Exp. 17, 293-303 (2009)
[10] Takafumi Hatano, Baku Nishikawa, Masanobu Iwanaga, and Teruya Ishihara, “Optical rectification effect in 1D metallic photonic crystal slabs with asymmetric unit cell,” Opt. Exp. 16, 8236-8241 (2006)
[11] Kyujung Kim, Soon Joon Yoon, and Donghyun Kim, “Nanowire-based enhancement of localized surface plasmon resonance for highly sensitive detection: a theoretical study,” Opt. Exp. 14, 12419-12431 (2008)
[12] Ming-Wei Tsai, Chia-Yi Chen, Yu-Wei Jiang, Yi-Han Ye, Hsu-Yu Chang, Tzu-Hung Chuang et al., “Coupling between surface plasmons via thermal emission of a dielectric layer sandwiched between two metal periodic layers,” Appl. Phys. Lett. 91, 213104 (2007)
[13] Ming-Wei Tsai, Tzu-Hung Chuang, Chao-Yu Meng, Yi-Tsung Chang, and Si-Chen Lee, “High performance midinfrared narrow-band plasmonic thermal emitter,” Appl. Phys. Lett. 89, 173116 (2006)
[14] Chin-Ming Wang, Yia-Chung Chang, Ming-Wei Tsai, Yi-Han Ye, Chia-Yi Chen, Yu-Wei Jiang et al., “Reflection and emission properties of an infrared emitter,” Opt. Exp. 12, 14673-14678 (2007)
[15] Yi-Han Ye, Yu-Wei Jiang, Ming-Wei Tsai, Yi-Tsung Chang, Chia-Yi Chen, Dah-Ching Tzuang et al., “Localized surface plasmon polaritons in Ag/SiO2/Ag plasmonic thermal emitter,” Appl. Phys. Lett. 93, 033113 (2008)
[16] Yi-Tsung Chang, Yi-Han Ye, Dah-Ching Tzuang, Yi-Ting Wu, Chieh-Hung Yang, Chi-Feng Chan et al., “Localized surface plasmons in Al/Si structure and Ag/SiO2/Ag emitter with different concentric metal rings,” Appl. Phys. Lett. 92, 233109 (2008)
[17] Yi-Han Ye, Yu-Wei Jiang, Ming-Wei Tsai, Yi-Tsung Chang, Chia-Yi Chen, Dah-Ching Tzuang, Yi-Ting Wu, and Si-Chen Lee, “Coupling of surface plasmons between two silver films in a Ag/SiO2/Ag plasmonic thermal emitter with grating structure,” Appl. Phys. Lett. 93, 263106 (2008)
[18] N. W. Ashcroft, and N. D. Mermin, “Solid State Physics”(Harcount).
[19] M. A. Ordal, Robert J. Bell, R. W. Alexander. Jr, L. L. Long, and M. R. Querry, “Optical properties of fourteen metals in the infrared and far infrared: Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W.,” Opt. Soc. Am. 24, 4493-4499 (1985)
[20] 邱燦賓, “電子束微影技術之鄰近效應修正,” 奈米通訊. 第七卷, 31 (2000)
[21] http://www.microchem.com
[22] http://www.jcnabity.com
[23] St´ephane Collin, Fabrice Pardo and Jean-Luc Pelouard, “Waveguiding in nanoscale metallic apertures,” Opt. Exp. 15, 4310-4320 (2007)
[24] M.G. Moharam, E.B. Grann, D.A. Pommet, and T. K. Gaylord, “Formulation for stable and efficient implementation of the rigorous coupled-wave analysis of binary gratings,” J. Opt. Soc. Am. A 12, 1068-1076 (1995);
[25] M.G. Moharam, D.A. Pommet, E.B. Grann, and T. K. Gaylord “Stable implementation of the rigorous coupled-wave analysis of surface-relief gratings: enhance transmittance matrix approach,” J. Opt. Soc. Am. A 12, 1077-1086 (1995)
[26] E. D. Palik, Handbook of Optical Constants of Solids (Academic Press, Boston, 1985)