A peak enhancement of frequency response of waveguide integrated silicon-based germanium avalanche photodetector  

作　　者：Linkai Yi Daoqun Liu Wenzheng Cheng Daimo Li Guoqi Zhou Peng Zhang Bo Tang Bin Li Wenwu Wang Yan Yang Zhihua Li 

机构地区：[1]Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China [2]School of Electronic Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Semiconductors》2024年第7期61-68,共8页半导体学报（英文版）

摘　　要：Avalanche photodetectors(APDs) featuring an avalanche multiplication region are vital for reaching high sensitivity and responsivity in optical transceivers. Waveguide-coupled Ge-on-Si separate absorption, charge, and multiplication(SACM)APDs are popular due to their straightforward fabrication process, low optical propagation loss, and high detection sensitivity in optical communications. This paper introduces a lateral SACM Ge-on-Si APD on a silicon-on-insulator(SOI) wafer, featuring a 10 μm-long, 0.5 μm-wide Ge layer at 1310 nm on a standard 8-inch silicon photonics platform. The dark current measures approximately 38.6 μA at-21 V, indicating a breakdown voltage greater than-21 V for the device. The APDs exhibit a unitgain responsivity of 0.5 A/W at-10 V. At-15 V, their responsivity reaches 2.98 and 2.91 A/W with input powers of-10 and-25 dBm, respectively. The device's 3-dB bandwidth is 15 GHz with an input power of-15 dBm and a gain is 11.68. Experimental results show a peak in impedance at high bias voltages, attributed to inductor and capacitor(LC) circuit resonance, enhancing frequency response. Furthermore, 20 Gbps eye diagrams at-21 V and-9 dBm input power reveal signal to noise ratio(SNRs) of 5.30. This lateral SACM APD, compatible with the stand complementary metal oxide semiconductor(CMOS) process,shows that utilizing the peaking effect at low optical power increases bandwidth.

关 键 词：PHOTODETECTORS optical communications RESPONSIVITY 3-dB bandwidth 

分 类 号：TN25[电子电信—物理电子学]