應用於生醫感測與高速網路之互補式金氧半光偵測器

Abstract

本研究提出四種應用於生醫感測與高速網路之積體互補式金氧半(CMOS)光偵測器，研究內容包含了設計、分析、製作、與量測。在生醫感測的應用上，提出P＋/Nwell指狀光二極體(finger photodiode)搭配轉阻放大電路(trans-impedance amplifier)，可量測過氧化氫(H2O2)、葡萄糖(glucose)與組織胺(histamine)的最低濃度分別為1 μM、1 μM與10 μM；提出基板浮接(floating bulk)環狀光電晶體(ring-shaped phototransistor)搭配外環光二極體，在可見光波段具有高於1000 A/W的響應度(responsivity)，對於辣根過氧化□(HRP)的檢測極限為2.7 pM。在高速網路的應用上，提出的網狀空間調變光二極體(spatially modulated photodiode)，可有效地把光電流中的慢速成分扣除，所設計製作的元件展現出5.5 GHz的高頻寬；提出之具深Nwell層的PIN光二極體，其深Nwell層被連接到高電位以排除在Psub層所產生的慢速擴散載子，所設計製作的元件對於50 Ω負載可達800 mVpp輸出電壓與2.5 Gbps操作速度。所開發之光偵測器效能皆比文獻上其他金氧半光偵測器高。

The design, analysis, manufacture, and measurements of the four integrated CMOS photodetectors for biomedical detections and high-speed networks are presented. For biomedical applications, the proposed P＋/Nwell finger photodiode with a trans-impedance amplifier demonstrated that the minimum concentration successfully detected for H2O2, glucose, and histamine were 1 μM, 1 μM, and 10 μM, respectively; the proposed ring-shaped phototransistor with a floating bulk enclosed by a ring-shaped photodiode exhibited a responsivity higher than 1000 A/W for the visible spectrum range and a detection limit of 2.7 pM for HRP (horse-radish peroxidase). For high-speed applications, the meshed SMPD (spatially modulated photodiode) can effectively subtract the deferred portion from the immediate portion of the photocurrent, and the manufactured device demonstrated a high bandwidth of 5.5 GHz; the proposed DNW-based (deep-Nwell-based) PIN photodiode, in which the slowly diffusive carriers generated in Psub are decoupled from the photocurrent by connecting the DNW to a positive supply voltage, was capable of outputting 800 mVpp with up to 2.5 Gbps for 50-Ω loads. These proposed photodetectors exhibited better performances than other reported CMOS photodetectors.