矽基可見光及紫外光感測元件

Abstract

本論文中，總共分兩大論點，分為模擬的部分和實驗的部分。 模擬的部分聚焦在矽的p-n 可見光及紫外光二極體，而實驗部分是有關於金氧半電容紫外光穿隧二極體。由於光吸收區域主要在空乏區內,設計時需要考慮吸收深度，即吸收係數的倒數。 我們利用模擬使用手指狀二極體來增益短波長光響應，於是，手指狀二極體及針扎光電二極體相減後可以得到相減光響應。因此，p-n二極體可做出紫外光偵測器。我們也使用金氧半電容穿隧二極體來做紫外光偵測器。銀閘極比鋁閘極更好的原因是在波長為320奈米處有個穿透。藉由調整銀的厚度，我們可調變頻譜由寬紫外光到UVB波段。 抗反射層減少反射來增加光偵測器的光響應。然而與基材的介面處需要考量介面缺陷。缺陷會損耗紫外光光響應而同時增加可見光光響應。最後我們做了結論和未來的工作。

The thesis is divided into two parts, simulation and experiment. The simulation part focuses on the silicon p-n visible/UV photodiode and the experiment part is related to the MOS UV tunneling photodetector respectively. Due to the photo-generation region mainly in the depletion region, the absorption length which is the reciprocal of the absorption coefficient needs to compare with this region in the design. We use finger-shaped diodes to enhance the short-wavelength responsivity in the simulation, and then, the reduced responsivity can be obtained from the finger-shaped diode and the pinned photodiode. Thus, the UV photodetector based on silicon p-n junction is demonstrated. We also show MOS tunneling diode as a potential device to detect the UV radiation. Ag gate metal has a better performance prior to Al with a transmission loss at =320nm. By adjust the Ag thickness, the MOS tunneling diode allows the selectivity in the broad UV to UVB region. The anti-reflection coating can enhance the detectors’ performance by reducing the reflectance. However, the interface-state traps need to be considered as the coating on the optical devices. We sows the traps will degrade the responsivity in the UV range while that in the visible still increase. Finally, we make conlusions and future work.