陳永芳臺灣大學：物理研究所洪暐強Hung, Wei-ChiangWei-ChiangHung2007-11-262018-06-282007-11-262018-06-282006http://ntur.lib.ntu.edu.tw//handle/246246/54551在這篇論文中，我們使用高解析度的拉曼光譜儀、螢光 光譜儀，以及掃描式電子微影等等技術，來研究奈米矽結構 的光學特性。 在我們的樣品中，矽的尖端只有大約4 奈米左右大小， 在此尺寸下，聲子的侷限效應是顯著的。我們研究了因為小 尺寸所引起的動量選擇規則鬆弛效應。並且實際上在螢光光 譜圖中，看到了不需要聲子協助的載子複合放光(大約1.15 電子伏特)。 除此之外，我們亦看到了在奈米矽尖柱中，有高於塊材 矽晶圓許多的拉曼訊號。對於奈米尺寸矽的研究，對於半導 體工業界是愈來愈重要的。我們希望這些研究的成果，能夠 對於以矽為主體的光電元件有很好的貢獻。In this thesis, we use high-resolution Raman and photoluminescence spec- troscopy to investigate the e¤ect of quantum con…nement at dry etched sili- con nanotips. We …rmly establish that the phonon con…nement occur at the silicon nanotips. In addition, we observe an enhanced photoluminescence intensity of no-phonon transitions which may be due to the relaxation of momentum selection rule in silicon nanotips. Besides, an enhanced Raman scattering from the silicon nanotips that might be attributed to the strong internal …eld was also investigated. The research for small-sized silicon is quite important in nowadays semiconductor industry. We hope that the obtained information would be useful to enhance the prospects for realizing the integration of Si based optoelectronic devices and would o¤er as guideline for further application.Contents 1 Introduction 11 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.2 Photoluminescence spectroscopy . . . . . . . . . . . . . . . . . 13 1.2.1 Introduction to photoluminescence spectroscopy . . . . 13 1.2.2 The application of photoluminescence spectroscopy . . 14 1.2.3 Limitations of photoluminescence spectroscopy . . . . . 17 1.2.4 Photoluminescence spectroscopy apparatus . . . . . . . 17 1.3 Raman spectroscopy . . . . . . . . . . . . . . . . . . . . . . . 19 1.3.1 Introduction to Raman scattering . . . . . . . . . . . . 19 1.3.2 Mechanism of stokes shift and anti-stokes shift . . . . . 20 1.3.3 Applications of Raman spectroscopy . . . . . . . . . . 21 1.3.4 Raman spectroscopy apparatus . . . . . . . . . . . . . 23 1.4 Silicon nanotips . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2 Theoretical background 33 2.1 Indirect and direct band . . . . . . . . . . . . . . . . . . . . . 33 2.2 Spatial correlation model . . . . . . . . . . . . . . . . . . . . . 34 2.2.1 Correlation length . . . . . . . . . . . . . . . . . . . . 35 2.3 Relaxation of q-selection rule . . . . . . . . . . . . . . . . . . 36 2.4 The downshift and asymmetric broadening of Si Raman peak . 38 3 Experiments and Analysis 45 3.1 Prediction of the existence of phonon localization . . . . . . . 45 3.2 The …rst thing to note . . . . . . . . . . . . . . . . . . . . . . 45 3.3 Evidence of the small sized e¤ect . . . . . . . . . . . . . . . . 48 3.4 Local temperature in silicon nanotips . . . . . . . . . . . . . . 50 3.5 Further investigation of the silicon nanotips . . . . . . . . . . 52 3.6 Correlation length . . . . . . . . . . . . . . . . . . . . . . . . . 54 3.7 The photoluminescence spectra of silicon nanotips . . . . . . . 56 3.8 The enhanced Raman scattering from silicon nanotips . . . . . 60 4 Summary 675873499 bytesapplication/pdfen-US矽奈米光學silicon nanostructuresthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54551/1/ntu-95-R90222035-1.pdf