矽光波導除了應用於光通訊，過去二十多年再生醫感測的領域也有蓬勃的發展，特點為高靈敏度、高穩定性、反應迅速且易於量產，其應用包括醫藥、環境、食品、國防等。生醫感測器依其偵測的物質，有以下幾種應用: (1)環境污染監測 (2)生物科技 (3)醫學檢驗與感測 (4)食品與農業監測。
生物感測器將生物分子固定於表面當作感應元件，利用生物分子間的交互作用和匹配性，達到和待測物間所產生的專一性與高靈敏度之反應，後續再將生物分間反應變化以光學、電學、磁學…等方式，進行定性或定量的成份分析。表面電漿共振為發生在金屬薄膜與介電質介面之間，電子的集體震盪現象。將此特性應用於表面電漿共振生物感測器，其具有免標識、即時檢驗、專一性和高靈敏度…等特性。本論文中，我們將探討表面電漿生物感測器(Surface Plasmon Biosensor)之模擬設計和製程開發。
表面電漿生物感測器的歷史中，最先提出有關表面電漿感測器應用於光波導製程的文章為J.Homola於1997年所提出，而在2006年P.Debackere也提出不同結構的文章，而我們提出更不同且擁有較好的靈敏度的結構。在半導體製程中，J.Homola和P.Debackere的結構採取矽波導感測區上覆蓋金屬，而J.Homola覆蓋Cr、Au、TaO5三層金屬，另外，P.Debackere則選擇先蝕刻感測區矽波導60nm再覆蓋Au厚度為60nm的單層金屬，至於，我們提出的新結構為先蝕刻矽波導感測區70nm再直接覆蓋Al 厚度為70nm。我們的優勢為包覆金屬製程比表面單層金屬製程來的簡易，單層金屬於感測區矽波導需要蝕刻包覆好的三面金屬，需要蝕刻側壁兩面金屬層，會造成側壁粗糙度和側壁金屬殘留於矽波導，導致靈敏度降低，因此，我們提出三面金屬包覆於感測區矽波導層，來降低側壁粗糙度對我們表面電漿生物感測器靈敏度的影響。
表面電漿生物感測器是利用波導耦合來產生表面電漿效果，本論文已進行表面電漿生物感測器的模擬與未來元件之製程步驟設計，論文中分別使用商業軟體Omnisim與Fimmwave中的FDTD和FDM進行數值模擬表面電漿波導之金屬厚度、長度、波導寬度對表面電漿現象之分析，根據模擬結果，在光通訊波段1520 nm~1570 nm中，元件寬度0.45 μm、金屬Al-Si-Cu嵌入厚度0.07 μm與長度10 μm，能夠產生極佳的表面電漿現象。

In the past two decades, silicon based biomedical sensors with high sensitivity, high stability, rapid response and easy production have vigorous development besides optical fiber communication spplications, which includes the analyses on the pharmaceutical, environmental, and food. The detected analytes by biomedical sensors can be categorized as follows: (1) Environmental pollution monitoring (2) Biotechnology (3) Medical laboratory test (4) Food and agricultural monitoring.
Biosensors should identify the biomolecules and then immobilize them onto the surface for sensing. The biological interactions and matching demonstrate the specification and high sensitivity. Then the reaction in optical, electrical, magnetic, ... etc., will be conducted in qualitative or quantitative composition analysis. Surface plasmon is a physical phenomenon that happens in the interface between metal and dielectric materials. This interaction is real time, high sensitivity and label-free detection and suitable for surface plasmon biosensing on small amount of biological and immunochemistry materials. In this thesis, we will explore the design and processing on the surface plasmonic biosensor.
In the development of surface plasmon resonance (SPR), J. Homola first proposed SPR biosensing on optical waveguides in 1997. In 2006, P. Debackere promoted this idea and demonstrated on the silicon-wire waveguides. In this thesis a silicon based optical waveguide is utilized as the biological sensors through surface plasma polaritons. The main structure is to implement the surrounding metals on top of the silicon-wire waveguide. When the optical mode is interfered with the metal, a surface plasma wave will be induced in the interface between the metal and dielectric film, same as the other metal interfaces. At the end of the surface plasmon region, all the interference will be joined together and coupled to the silicon-wire. This mechanism is equivalent to the function of Mach Zehnder interferometer (MZI). The simulation results are showing that the sensitivity is up to 2891 nm/Refractive Index Unit (RIU) and the details will be further discussed. Due to the lithography limitation from the National Nano Device Laboratories(NDL), the silicon-wire width is chosen 450 nm and 3 μm for simulation verification. This new surface plasmon silicon-wire biosensor owns the easy processing and furthermore reduce the propagation loss because of the waveguide sidewall covered by the metal.
The functions of FDTD (Finite Difference Time Domain) and FDM (Finite Difference Method), built in the commercial software of OmniSim and FIMMWAVE respectively, are taken to calculate the surface plasmon based silion-wire under the processing variation of the metal thickness, waveguide length and width. The optimized sensitivity is demonstrated under the waveguide width of 450 nm, the Al-Si-Cu thickness of 70 nm, and the waveguide length of 10 μm at the wavelengths range from 1520 nm to 1570 nm.

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