近年來，短波紅外光在消費性電子產品中的應用顯著增加，涵蓋智慧手錶的辨
識技術、自駕車技術、生醫檢測以及半導體產業中材料缺陷的檢測等多個領域，充
分彰顯其技術的重要性。鍺錫材料具備高電子與電洞遷移率，能有效提升運算性能
並降低能耗，此外，其可與現有矽基技術實現高度整合，特別是在矽光子技術領域
中，展現出多項優勢，對於電子設備之研發具備極大潛力與發展前景。
本研究採用四氯化鍺與四氯化錫作為前驅物，以氫氣作為載氣，利用電漿輔助化學氣相沉積法（PECVD），並透過鹵素燈對玻璃管腔體進行加熱，在矽基板上沉積鍺薄膜與鍺錫薄膜。於薄膜製程方面，主要目標為錫含量達10%、鬆弛應變及減少缺陷，以提升薄膜的光致發光強度；同時，通過提升電漿功率及優化系統壓力，降低氯元素殘留所引起的陷阱輔助復合(trap-assisted recombination）。元件製程部分，採用化學濕式蝕刻技術製作異質結構之PIN光偵測器，以及光導體結構光偵測器。利用光致發光與響應率量測系統，結合鎖相放大器對薄膜與元件性能進行量測與分析。
透過本研究發現，在低溫(100  °C)生長時生長的鍺錫薄膜，殘留的氯會造成陷阱輔助復合，導致光電導體光偵測器與光電二極體光偵測器的響應率下降，而殘留的氯也會導致非故意摻雜，導致光電導體光偵測器的響應率下降。在二次離子質譜儀(SIMS)量測結果顯示，使用低溫(100  °C)生長的鍺錫薄膜有嚴重的氯殘留，約為
高溫(470  °C)生長鍺薄膜的200倍。在1.8 μm – 2.5 μm波長範圍，製作出的PIN結
構光偵測器之響應率約為2×10^(-4) A/W，光導體結構光偵測器之響應率為1×10^(-1) A/W，兩者所量測的訊號與背景訊號非常接近。在未來可以透過增加電漿功率、提升生長溫度與減少質子轟擊，以此方向來優化鍺錫薄膜生長參數，並製作 PIN 結構光偵測器與光導體結構光偵測，提升元件性能。

In recent years, the application of short-wave infrared (SWIR) light has significantly expanded across various consumer electronics domains, including recognition technologies in smartwatches, autonomous vehicle systems, biomedical diagnostics, and defect detection in semiconductor materials, highlighting its technological significance. GeSn materials, characterized by high electron and hole mobilities, show great potential
in enhancing computational performance and reducing power consumption. Furthermore, GeSn's compatibility with existing silicon-based manufacturing processes facilitates seamless integration with silicon photonics, paving the way for next-generation electronic devices.
With additional halogen lamp heating applied to the glass chamber, the plasma enhanced chemical vapor deposition (PECVD) method used in this study employed GeCl4 and SnCl4 as precursors, with H₂ gas as the carrier, to deposit germanium and germanium–tin thin films on silicon substrates. The primary objectives are to achieve a tin (Sn) concentration of 10%, realize effective strain relaxation, and significantly reduce defect density, thereby enhancing the photoluminescence intensity of thin films. Concurrently, the RF power and gas pressure were optimized to reduce trap-assisted recombination caused by chlorine residues. In addition, chemical wet etching was applied to fabricate photodetectors with heterojunction PIN and photoconductor configurations. The performance of thin films and devices was measured and analyzed in this study using photoluminescence and responsivity measurement systems integrated with a lock-in amplifier.
Results show that GeSn films grown at a low temperature of 100 °C retain significant chlorine residues, which induce trap-assisted recombination and lead to reduced responsivity in both fabricated photoconductor-type and PIN photodetectors. The residual chlorine also causes unintended doping, further degrading the responsivity of the photoconductor-type photodetectors. Secondary Ion Mass Spectrometry (SIMS) analysis indicates that the chlorine concentration in GeSn films grown at 100 °C is approximately 200 times higher than that in Ge films grown at 470 °C. Within the wavelength range of 1.8 μm to 2.5 μm, the fabricated PIN photodetector exhibits a responsivity of approximately 2×10^(-4) A/W, while the photoconductor-type detector shows a responsivity of about 1×10^(-4) A/W, both of which are close to the background signal level. Future work will focus on optimizing GeSn growth parameters: such as increasing RF power, raising the growth temperature, and minimizing proton bombardment to improve film quality and enhance the performance of both PIN and photoconductor-type photodetectors.