不同Ge组分a-Si_(1-x)Ge_(x)键合层对InGaAs/Si雪崩光电二极管性能的影响  

Effect of a-Si_(1-x)Ge_(x)Bonding Layer with Different Ge Compositions on the Performance of InGaAs/Si Avalanche Photodiode

作　　者：周锦荣 鲍诗仪 佘实现 黄志伟 柯少颖 ZHOU Jinrong;BAO Shiyi;SHE Shixian;HUANG Zhiwei;KE Shaoying(College of Physics and Information Engineering,Minnan Normal University,Zhangzhou,Fujian 363000,China)

机构地区：[1]闽南师范大学物理与信息工程学院,福建漳州363000

出　　处：《光子学报》2022年第9期118-127,共10页Acta Photonica Sinica

基　　金：National Natural Science Foundation of China(Nos.62004087,12164051);Natural Science Foundation of Fujian Province(No.2020J01815);the Natural Science Foundation of Zhangzhou(No.ZZ2020J32).

摘　　要：采用非晶半导体中间层键合(SIB)实现键合界面失配晶格的阻断是实现高质量Si基InGaAs薄膜制备的最佳选择。本文在InGaAs/Si键合界面插入一层非晶锗硅(a-Si_(1-x)Ge_(x))键合层,模拟了不同Ge组分对InGaAs/Si APD复合率、能带、隧穿、电荷堆积等参数的影响。器件在室温下获得极低的暗电流(~10^(-10) A@95%雪崩电压),增益和增益带宽积分别高达30 GHz和60 GHz。本文将为低噪声近红外APD的研制提供理论指导。Avalanche Photodiode(APD)is a highly sensitive photodetector for fiber-optic transmission systems.InGaAs/InP APD is difficult to be operated at near-room-temperature with low noise due to the high k value(0.4~0.5)of InP material.The combination of InGaAs material with Si material is an ideal solution for the fabrication of APD ascribed to the low k value(0.02)of Si material.Nevertheless,highquality InGaAs film is difficult to be grown on Si material using epitaxial growth techniques.This attributes to the fact that the lattice mismatch between InGaAs and Si is as high as 7.74%.Semiconductor Interlayer Bonding(SIB)based on the amorphous material can eliminate the effect of mismatched lattices between InGaAs and Si.However,the effect of amorphous semiconductor material on the performance of InGaAs/Si APD is still unclear.In this work,an a-Si_(1-x)Ge_(x)bonding layer is inserted at InGaAs/Si bonded interface to isolate the lattices between InGaAs and Si.The recombination rate,energy band,tunneling,and charge accumulation of InGaAs/Si APD are simulated.It shows that as the bandgap increases,The dark and optical current rise first and then fall.This is consistent with the trend of the recombination rate.Although the recombination rate in the a-SiGe layer shows a downward trend,the dark current of the entire device is not seriously affected becausethe thickness of the a-SiGe bonding layer is thin.A gap is formed between the optical and dark current curves,which is different from the conventional APD.It is noticeable that such a gap is beneficial to reduce the device noise due to the low dark current of the device.At this point,the InGaAs/Si APD with extremely low dark current(~10^(-10) A@95%breakdown voltage)is obtained at room temperature.In addition.as the bandgap increases,the electron concentration in the a-SiGe layer does not change drastically,while the hole concentration in the a-SiGe layer decreases significantly,leading to a decrease in the recombination rate in the a-SiGe layer.This results from the decrease

关 键 词：InGaAs/Si雪崩光电二极管 a-SiGe键合层 暗电流 增益带宽积 

分 类 号：TN315[电子电信—物理电子学]