近年來，許多電子產品的傳輸速率和處理速率越來越高，因此周邊的傳輸線路也需要能應付高速的傳輸需求。而近十年來，以矽和二氧化矽為主的各種矽基光電元件不斷的被發表出來。這之中包括光源，光調變器和偵測器。因此以光傳輸取代傳統晶片間的資料傳輸的雛形已然形成。而這之中一篇Intel2004年在nature上發表的論文使用類似傳統MOS的結構製作光調變器，其調變速度可達到2.5GHz。然而主要限制此種元件操作速度的部份是閘極多晶矽的電阻。傳統降低閘極多晶矽電阻的方法是種滲雜，但因為在光電的應用上滲雜濃度太高會使消光係數過高，因此必須尋求其他方法降低閘極多晶矽的電阻。由於載子移動率μ和濃度及電阻率ρ的關係為μ=1/Nqρ，其中q是電子的單位電荷，N是載子濃度。因此尋求更高的載子移動率便是改善閘極多晶矽的電阻的主要方法。近年不斷的有文獻指出雷射退火可以得到更大的晶粒，更好的多晶矽膜電性。但是這些研究往往集中在玻璃基板或是下方有很厚的氧化層上方的非晶矽膜的雷射退火。然而使用在光電元件閘極下方的氧化層厚度都相當薄，如果要將雷射退火用在光電元件的閘極上，就需要先實驗測試雷射退火使用在閘極上的非晶矽膜的效果以及對閘極氧化層的影響。因此本論文的目的是嘗試在薄的氧化層上的非晶矽膜進行雷射退火的效果以及對閘極氧化層的影響。實驗的方法是在矽晶圓上成長12nm的閘極氧化層後沉積不同厚度的非晶矽膜，再使用不同的雷射退火條件退火，之後進行電容和霍爾量測樣品的製作及分析以得到雷射退火的效果以及對閘極氧化層的影響。結論是在一個12nm氧化層上疊100nm的非晶矽膜並進行雷射退火，要藉由控制能量的使氧化層不被破壞是可行的，但是在這樣的能量範圍內得到的載子移動率較傳統固相結晶法得到的值低了約15%。因此這樣的結構無法使用雷射退火讓結晶更大。但是霍爾量測這個方法的確是量出薄膜電性的一個好的測量方法。

[1]A..Liu, R..Jones, L. Liao, D.Samara-Rubio, D.Rubin, O.Cohen, R.Nicolaescu,
and M.Paniccia, ``A high-speed silicon optical modulator based on a metal–oxide–semiconductor capacitor,'' NATURE, vol.427, p.615,2004.

[2]R.A. Soref and B.R. Bennett, ``Electrooptical effects in silicon,'' IEEE JOURNAL OF QUANTUM ELECTRONICS,., vol.QE-23, p.123, 1987.

[3]H.W. Zan, C.Y. Huang, K.Saito, K.Tamagawa, J.Chen, and T.J. Wu, ``The crystallization mechanism of poly-si thin film using high-power Nd:YAG laser with gaussian beam profile,'' Materials Research Society, vol.910, p.0910--A14--03, 2006.

[4]C.-C. Tsai, Y.-J. Lee, K.-Y. Chiang, J.-L. Wang, I.-C. Lee, H.-H. Chen, K.-F. Wei, T.-K. Chang, B.-T. Chen, and H.-C. Cheng, ``Polycrystalline silicon thin-film transistors with location-controlled crystal grains fabricated by excimer laser crystallization,'' APPLIED PHYSICS LETTERS, vol.91, p.201903--1, 2007.

[5]H.Rong, S.Xu, Y.-H. Kuo, V.Sih, O.Cohen, O.Raday, and M.Paniccia, ``Low-threshold continuous-wave raman silicon laser,'' nature photonics, vol.1, p.232, 2007.

[6]M.W. Geis, S.J. Spector, M.E. Grein, R.T. Schulein, J.U. Yoon, S.D. D.M.Lennon, F.Gan, F.X. Kaertner, and T.M. Lyszczarz, ``CMOS-compatible all-si high-speed waveguide photodiodes with high responsivity in near-infrared communication band,'' IEEE PHOTONICS TECHNOLOGY, vol.19, p.152, 2007.

[7]Q.Xu, S.Manipatruni, B.Schmidt, J.Shakya, and M.Lipson, ``12.5 gbit/s carrier-injection-based silicon microring silicon modulators,'' OPTICS EXPRESS, vol.15, p.430, 2007.

[8]L.Gu, W.Jiang, X.Chen, L.Wang, and R.T. Chen, ``High speed silicon
photonic crystal waveguide modulator for low voltage operation,'' APPLIED PHYSICS LETTERS, vol.90, pp.071105--1, 2007.

[9]A.Liu, L.Liao1, D.Rubin, H.Nguyen, B.Ciftcioglu, Y.Chetrit, N.Izhaky, and M.Paniccia, ``High-speed optical modulation based on carrier depletion in a silicon waveguide,'' OPTICS EXPRESS, vol.15, p.660, 2007.

[10]A.W. Poon, L.Zhou, C.Li, N.K. Hon, and H.Chen, ``Microring and microdisk resonator integrated circuits on a silicon chip,'' Procedding of SPIE, vol.6476, p.647607--1, 2007.

[11]A.Mimura, N.Konishi, J.K.Ono, Y.Hosokawa, Y.Ono, T.Suzuki, K.Miyata, and H.Kawakami, ``High performance low-temperature poly-si n-channel TFTs for LCD,'' IEEE Transactions Electron on Device, vol.36, p.351, 1989.

[12]S.Uchikoga and N.Ibaraki, ``Low temperature poly-si TFT-LCD by excimer laser
anneal,'' Thin Solid Films, vol.383, p.19, 2001.

[13]Y.F. Chong, Hans-Joachim, L.Gossmann, K.-L. Pey, M.O. Thompson, A.T.S. Wee, and C.H. Tung, ``Laser thermal processing of amorphous silicon gates to reduce poly-depletion in CMOS devices,'' IEEE TRANSACTIONS ON ELECTRON
DEVICES, vol.51, p.669, 2004.

[14]T.Yamamoto, K.Okabe, T.Kubo, K.Goto, H.Morioka, Y.Wang, T.Lin, S.Talwar, M.Kase, and T.Sugii, ``Novel polysilicon gate engineering with a laser thermal process for sub-40 nm CMOS devices,'' Solid-State Electronics, vol.48, p.1837, 2004.

[15]M.O. Thompson, ``Melting temperature and explosive crystallization of amorphous silicon during pulsed laser irradiation,'' Physics Review Letter, vol.52, p.2360, 1984.

[16]L.J. vander PAUW, ``A measureing of specific resistivity and hall effect of disc or arbitrary shape,'' Philips Research Report, vol.13, p.1, 1958.

[17] HL5500PC Hall Effect Measurement System User's Manual. p.2-1

[18]B.E.A. Saleh and M.C. Teich, Fundamentals of Photonics.Wiley Interscience, 1991.

[19]J.D. plummer, M.Deal, and P.B. Griffin, Silicon VLSI Technology. Prentice Hall, 2000.

[20]F.S. d'Aragona, ``Dislocation etch for (100) planes in silicon,'' Journal of Solid-State Science and Technology, p.948 (1972)
.
[21]Y. Helen, R. Dassow, M. Nerding, K. Mourgues, F. Raoult, J.R. K¨ohler, T. Mohammed-Brahim, R. Rogel, O. Bonnaud, J.H. Werner, H.P. Strunk ``High mobility thin film transistors by Nd:YVO4-laser crystallization, Thin Solid Films, vol.~383, p.~143, 2001.

[22]Chun-Chien Tsai, Hsu-Hsin Chen, Bo-Ting Chen, and Huang-Chung Cheng ``High-Performance Self-Aligned Bottom-Gate Low-Temperature Poly-Silicon Thin-Film Transistors With Excimer Laser Crystallization,'' APPLIED PHYSICS LETTERS, vol.~28, p.~599, 2007.

[23]Chun-Chien Tsaia ``Polycrystalline silicon thin-film transistors with location-controlled crystal grains fabricated by excimer laser crystallization,'' APPLIED PHYSICS LETTERS, vol.~97, p.~201903-1, 2007.

[24]Ching-Wei Lin
Fabrication and Characterization of High performance Low Temperature Polycrystalline Silicon thin Film Transistors. PhD thesis, NCTU Department of Electronic Engeneering, chapter2，，2002.