雪崩光电二极管的Monte Carlo模拟及器件制作

发布时间：2018-05-14 19:05

本文选题：雪崩光电二极管 + 碰撞离化　；参考：《华中科技大学》2015年硕士论文

【摘要】：在长距离的光纤通信系统中,由于传输损耗而造成光信号微弱问题十分突出。雪崩光电二极管(APD)由于其内部增益,灵敏度通常比PIN二极管高5~10 dB。高速APD因为高灵敏度和足够的速率被列入下一代光传输系统的规划中。其中InP/InGaAs APD在10Gbit/s以及更高速率的光通信系统中已有广泛的应用。近年来,由于InAlAs材料具有优秀的离化特性和更宽的带隙,使得InAlAs/InGaAs APD受到重视。但相比于InAlAs材料,InP APD的相关工艺更加成熟、产品可靠性也更好。因此,本文主要研究了适用于25 Gbit/s及更高速率的InP/InGaAs APD,并探索了基于空间离化的级联结构InP APD。为了研究和优化高速APD器件,本文对随机路径长度(RPL)模型针对吸收渐变电荷倍增分离(SAGCM)APD做了相应的扩展。并采用静态电场蒙特卡罗(MC)碰撞离化模型对电荷层的离化系数做了修正,并对其进行了验证。RPL模型所得脉冲响应通过延时、权重处理计算出器件的整体响应。再通过该脉冲响应结合暗电流、码间串扰(ISI)和带宽限制增益计算出相应的误码率(BER),从而得到各层参数对器件灵敏度的影响。相比于直接使用MC模型对整体器件进行模拟,该修正的RPL模型在保证精确度的同时大幅降低了模拟所需时间。所模拟结果显示出电荷层对高速SAGCM APD性能有很大影响,并且由于其相对于倍增层厚度更具有可调性的特点,从而可以起到在保证灵敏度的同时依据现有工艺来调节外延层离化区域结构参数的作用。对于InP低噪声级联APD的探索,本文首先通过MC模型对相应物理机制进行了分析,并分析验证了其可行性。再采用修正的弛豫效应理论(DSMT)模型和RPL模型分析了其增益-噪声特性、频率响应特性以及级联数目和外延层参数对其性能的影响,并在此基础上对外延层结构进行了简化和优化。此外,本文使用以锁相放大器为核心的测试平台对InP级联APD的I-V特性和噪声特性进行了测试。测试结果显示级联结构InP APD的噪声特性较体材料而言有显著改善。
[Abstract]:In long-distance optical fiber communication system, the problem of weak optical signal caused by transmission loss is very prominent. Because of its internal gain, the sensitivity of avalanche photodiode is usually 5 ~ 10 dB higher than that of PIN diode. High-speed APD is included in the next generation optical transmission system planning because of its high sensitivity and high speed. Among them, InP/InGaAs APD has been widely used in 10Gbit/s and higher rate optical communication systems. In recent years, InAlAs/InGaAs APD has attracted much attention due to its excellent ionization properties and wider band gap. But compared with the InAlAs material, the related technology of InP APD is more mature and the product reliability is better. Therefore, this paper mainly studies InP/InGaAs APDs suitable for 25 Gbit/s and higher rates, and explores the cascaded InP APDs based on spatial ionization. In order to study and optimize the high speed APD devices, the random path length (RPL) model is extended to absorb the gradual charge multiplication separation. The static electric field Monte Carlo (MC) collision ionization model is used to modify the ionization coefficient of the charge layer, and it is verified that the pulse response obtained from the RPL model can be calculated through delay, and the overall response of the device is calculated by weight processing. The corresponding bit error rate (BER) is calculated by combining the pulse response with dark current, ISI) and bandwidth-limited gain, and the influence of the parameters of each layer on the sensitivity of the device is obtained. Compared with the direct use of MC model to simulate the whole device, the modified RPL model can greatly reduce the simulation time while ensuring the accuracy. The simulation results show that the charge layer has a great influence on the performance of high speed SAGCM APD, and because of its more adjustable characteristics than the thickness of the multiplying layer, Thus, the structure parameters of the ionization region of the epitaxial layer can be adjusted according to the existing process while ensuring the sensitivity. For the exploration of InP low noise cascaded APD, the physical mechanism is analyzed by MC model, and its feasibility is verified. Then the gain noise characteristics, frequency response characteristics and the effects of the number of cascades and the parameters of epitaxial layers on their performance are analyzed by using the modified relaxation effect theory (DSMTM) model and the RPL model. On this basis, the epitaxial layer structure is simplified and optimized. In addition, the I-V and noise characteristics of InP cascaded APD are tested by using a phase-locked amplifier as the core test platform. The results show that the noise characteristics of cascaded InP APD are much better than that of bulk materials.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.11;TN312.7

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