| 摘要: | 短波紅外波段在通訊、感測器、醫療及車用等產業上具有重要的地位，其中以能夠穿透水、霧氣、矽基、生物組織，以及在1350/1550 nm擁有低散射、低吸收等特性作為研究方向。而鍺基材料在紅外波段擁有高穿透以及低吸收的光學性質，因此非常適合作為窄帶濾光膜中的高低折射率材料，並且以此設計出在短波紅外具有高品質的窄帶濾光膜，以延伸現今產業在近紅外波段850/940 nm的應用。
本實驗延續對鍺與鍺化合物的前期研究，前期研究中已經完成在製程溫度500°C的參數優化，並且成功製鍍出高穿透率的短波紅外窄帶濾光膜。而為了實際應用在晶圓級光學薄膜的製程中，考慮到後續黃光製程中光阻材料的熱穩定性，必須將製程溫度降低至相對低溫(200°C以下)，並繼續針對功率、反應氣體流量等製程參數進行優化，並以UV-IR光譜儀及軟體Essential Macleod分析薄膜光學性質；FTIR、XPS分析薄膜化學成分的組成；SEM、XRD、AFM分析薄膜的材料與表面性質，得到最佳化參數製鍍出高穿透的短波紅外窄帶濾光膜。
本實驗切分為三個部分，第一部份針對高折射率材料進行製程優化，依序以製程溫度、製程功率、氫氣通量作為製程調控，並且解決製程中電漿打火造成膜面有轟擊孔洞的問題，優化後薄膜呈非晶態且表面平坦，折射率達4.095，消光係數為7E-3。第二部分為延續前段製程溫度，在防止靶材毒化的前提下，做氧氣通量的調控進行優化，同時探討高氧通量下氧化鍺薄膜發生水解反應，優化後薄膜亦呈非晶態表面平坦，折射率達1.597，消光係數為4.5E-4。第三部分利用上述兩最佳化參數設計後製鍍在1350/1550 nm的窄帶濾光膜，實驗結果為中心波長穿透率分別達到87.9及88%，總膜厚為2及2.4μm達成高穿透率以及低膜厚的目標。
;Short-wave infrared (SWIR) wavelengths are crucial in communication, sensing, medical, and automotive industries due to their ability to penetrate water, fog, silicon, and biological tissues, and their low scattering and absorption at 1350/1550 nm. Germanium-based materials, with high transparency and low absorption, are ideal for narrowband filters. This study extends applications at near-infrared wavelengths of 850/940 nm by designing high-quality SWIR narrowband filters.
Building on previous research with optimized parameters at 500°C, this experiment reduces the deposition temperature to below 200°C for practical wafer-level applications. Further optimization of power and gas flow rates was conducted. The optical properties were analyzed using UV-IR spectroscopy and Essential Macleod software, and the chemical composition and material properties were examined using FTIR, XPS, SEM, XRD, and AFM. Optimized parameters resulted in high-transmittance SWIR narrowband filters.
The experiment is divided into three parts. First, the process for high-refractive-index materials was optimized by adjusting temperature, power, and hydrogen flow rate, addressing plasma arcing issues. The films achieved a refractive index of 4.095 and an extinction coefficient of 7E-3. Second, the oxygen flow rate was optimized to prevent target poisoning, achieving a refractive index of 1.597 and an extinction coefficient of 4.5E-4. Third, the optimized parameters were used to design narrowband filters at 1350/1550 nm, achieving center wavelength transmittance of 87.9% and 88% with film thicknesses of 2 μm and 2.4 μm.
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