Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, 1040 Vienna, Austria.
Sensors (Basel). 2023 Mar 23;23(7):3403. doi: 10.3390/s23073403.
This paper presents a CMOS-integrated dot avalanche photodiode (dot-APD) that features a small central n/p-well hemispherical cathode/p-well structure circularly surrounded by an anode ring. The dot-APD enables wide hemispherical depletion, charge collection from a large volume, and a small multiplication region. These features result in a large light-sensitive area, high responsivity and bandwidth, and exceptionally low junction capacitance. The active area can be further expanded using a multi-dot structure, which is an array of several cathode/p-well dots with a shared anode. Experimental results show that a 5 × 5 multi-dot APD with an active area of 70 μm × 70 μm achieves a bandwidth of 1.8 GHz, a responsivity of 9.7 A/W, and a capacitance of 27 fF. The structure of the multi-dot APD allows for the design of APDs in various sizes that offer high bandwidth and responsivity as an optical detector for various applications while still maintaining a small capacitance.
本文提出了一种 CMOS 集成点雪崩光电二极管（dot-APD），其特点是中央 n/p 阱半球形阴极/p 阱结构被阳极环圆形环绕。dot-APD 可实现宽半球形耗尽、从大体积收集电荷和小倍增区域。这些特点导致大的光敏面积、高响应度和带宽以及极低的结电容。使用多点点结构可以进一步扩展有源区，多点点结构是具有共享阳极的几个阴极/p 阱点的阵列。实验结果表明，具有 70μm×70μm 有源区的 5×5 多点 APD 实现了 1.8GHz 的带宽、9.7A/W 的响应度和 27fF 的电容。多点 APD 的结构允许设计各种尺寸的 APD，这些 APD 作为各种应用的光学探测器具有高带宽和响应度，同时仍保持小电容。
