Research On Key Technologies Of Flip-chip Bonding Of Heterogeneously Integrated ?-?-on-silicon Laser

In recent years,with the rapid development of Internet of things,artificial intelligence,5G communication and other information technologies,photonic integrated devices of stable performance,good reliability and high integration have become the technical basis of various new optical communication systems.Silicon photonic integrated devices can not only apply for most optical communication systems,but also be compatible with Complementary Metal-OxideSemiconductor(CMOS)manufacturing processes.Therefore,silicon photonics is one of the hottest topics in optical communications.At the present,the challenge of silicon photonic integration is that the material can not effectively emit light due to its indirect band gap.So,silicon-based heterogeneously integrated lasers are of vital importance both academic and industrial fields.This thesis focuses on the flip chip bonding and laser-induced forward transfer(LIFT)technology to integrate ?-? laser onto silicon-based passive waveguide,providing theoretical model and device prototype for high-performance silicon based on-chip light source.Firstly,the background and significance of the research on silicon-based heterogeneous integration are detailed.The research status domestic and abroad of heterogeneously integrated light source technology and bonding technology on silicon substrates are discussed in the thesis.Secondly,a finite difference beam propagation method(FD-BPM)by solving the full vector wave equation is also introduced.Based on the theoretical basis of semiconductor light emission and light transmission in the waveguide,a silicon-based heterogeneous integrated ?-? laser structure model coupled by evanescent wave is proposed.The ?-? laser is flip-chip bonded to the side of the silicon-based chip,and the size of the two chips are controlled so that the evanescent wave energy is coupled to the waveguide for transmission.The simulation shows that the optical coupling efficiency(CE)is 82% when the lateral separation between the active and passive regions is 1?m at the same height,while the CE is 66.7% when the separation increases to 6?m.As for the inverted conical laser,the longitudinal coupling length is 48?m.Then,based on the physical mechanism of photothermal effect for LIFT process,onedimensional heat conduction equation with the moving boundary of the Indium film as the donor is established.The melting boundary and temperature changes of the film when the indium film thickness is 25 nm,40nm,60 nm,and the light source irradiation energy is 3m J,6m J,12 m J are analyzed by numerical analysis.Furthermore,cross and vernier alignment markers both on active and passive devices for flipchip bonding are invented.On the other hand,Indium columns are grown by evaporation deposition on the silicon adapter plate electrode,and the bonding experiment of a certain type of semiconductor laser is carried out on FC150 semi-automatic high precision flip chip bonder from French SET company.The process parameters of thermosonic bonding such as pressure,temperature and time are preliminarily explored.Finally,the research is summarized and the follow-up work is prospected.