短波紅外光波段（SWIR）為不可見光，在1350 nm、1550 nm 波段有低散射、不被水吸收、能穿透矽、還能區分可見光無法分辨的細節，所以目前市場上短波紅外光感測器的需求在大量增加。而在感測器微型化跟元件整合的提升下，現有材料設計出的多層膜過厚，需要新的在紅外光波段低吸收的高折射率材料，來完成光學濾光片的應用。本研究將鍺和氧化鍺，作為高、低折射率材料，確認材料特性並實際應用。 鍺過去做為第一代半導體材料被廣泛研究，但在光學方面的研究較少。本實驗選擇反應式高功率脈衝磁控濺鍍來鍍製鍺薄膜。實驗分為三個部分：第一部分為確認製程參數，依序調變腔體溫度、功率、HiPIMS Duty Cycle，優化鍺薄膜的結構來獲得較佳光學特性。第二部分為調變氣體通量：藉由控制氫氣、氧氣個別通量和通時通入氫和氧，調整鍺薄膜中氫、氧摻雜量，確認氫、氧鍵結對鍺薄膜的影響。並確認鍺和氧化鍺作為高、低折射率材料的折射率和消光係數。第三部分為設計並鍍製多層膜：結合前兩部分的結果，以同腔體同靶材不同氣體摻雜量，實際濺鍍穿透窗於1550 nm和1350 nm的窄波通光學濾光片。 ;Shortwave infrared (SWIR) light, which is invisible, exhibits low scattering and low water absorption at 1350 nm and 1550 nm wavelength ranges. It can transmit silicon to resolve details that are not analyzed by visible light. Therefore, the demand for SWIR sensors has significantly increased in the market. However, the multilayer design for SWIR filters is too thick to achieve the advancements of miniaturization and integration. A high refractive index material with low absorption is necessary to develop SWIR filters. In this study, germanium and germanium oxide are used as high and low refractive index materials, respectively, to aim their characteristics and practical applications. Germanium is the first-generation semiconductor material, however there are less research about its optical properties. In this experiment, reactive high power impulse magnetron sputtering (HiPIMS) is chosen as the deposition method for germanium thin films. The experiment consists of three parts. Firstly, the process parameters are optimized by adjusting the fabricated temperature, power, and HiPIMS duty cycle to improve optical properties. Secondly, the gas flux is modulated by controlling the flow rates of hydrogen and oxygen, to adjust the hydrogen and oxygen doping concentration in the germanium thin films and then to evaluate the film properties such as the refractive index and extinction coefficient of germanium and germanium oxide. Lastly, based on the results from the previous two parts, multilayer SWIR filters are designed and fabricated in the same chamber and target materials with different working gases to achieve the narrowband pass filters for the transmission bands at 1550 nm and 1350 nm.
