Theoretical Research On InP-Based HBT And The Fabrication Of Monolithic OEIC Of Photoreceiver's Front End

The research works described in this paper were supported by the grants from many research projects, including Doctoral Subjects Research Grants of Ministry of Education, PRC, "Monolithic OEIC photoreceiver modules based on RCE photodetectors and HBT" (20020013010) and National Basic Research Program of China, "Basic Research on Integrated Optoelectronic Devices and Microstructure Optical Fibers with Structure and Technology Innovations for Future Advanced Optical Communications" (2003CB314900).InP-based HBT have many attractions in the field of Fiber-Optic communication, and they can integrate with photodetectors with shared epitaxial layers on a single substrate, which have the advantages of one-step epitaxy, simplicity of fabrication, and possibly higher reliability. As one kind of promising devices for high-speed application, the research on InP-based HBT has bright future and so attracts much attention in the world.This paper studied the theory and experimental fabrication of InP-based HBT, and its monolithic integration with PIN-photodetector. In this paper, the author has obtained the results as the following:(1) Systematically studied and summarized the physical parameters usually used in the theoretical model of HBT. Obtained the formulas of mobilities of InP and In_0.53Ga_0.47As semiconduct materials based on the released references, which takes an important role in the theoretical simulations of InP-based HBT;(2) Studied the influences of InP-based HBT's direct-current and high-frequency characteristics after Kirk Effect emerges under large current density, and obtained the result that the characteristics of both InP-based HBT's Direct Current and High Frequency will deteriorate after Kirk Effect happened. At the same time, this paper also studied the influences ofτ_b, f_? and f_max with X_s which is the distance of zero-electric field in the depletion layer of base-collector junction, and obtained the conclusion that the distance of X_s is unignorable compared with X_B especially in the case of Base thickness is very thin and Collector is very thick;(3) Studied the influences of InP-based HBT's characteristic parameters with the case that the Base is ununiformly doped. At first, the author studied the mechanism and composition of inner build-in electric field in the Base, and got the conclusion that the decelerating electric field of p-Ino.53Gao.47As semiconduct material resulted in Band Gap Narrowing Effect which led by graded base doping is unignorable compared with the accelerating electric field. Secondly, studied the influences ofτ_b, f_? and f_max with different doping curves of the Base, and got the conclusion that it has not very distinct improvement to the parameter of f_? of InP/In_0.53Ga_0.47As HBT. Thirdly, studied the influences ofτ_b, f_? and f_max with doping deviation to the assumed doping curve, and obtained the result that the influence of doping deviation to the deviation of f_? is very small. For instance, under the conditions of V_BE=0.64,α=2.78 andλ=0.38, 5% of doping deviation leads only 1 % of deviation to f_?;(4) The author participated in the fabrications of InP-based HBT, PIN-PD and the monolithic OEIC photoreceiver. The testing results of these devices described as the following: as to the 2μm size style of InP-based HBT, the parameter of f_? was 28GHz; as to the PIN-PD of 22×22μm² incidence area, the responding band of high frequency was 16GHz; as to the monolithic OEIC photoreceiver based on the above styles of PIN-PD and InP-based HBT, the responding band of high frequency was 3 GHz.