Design,Simulation,Fabrication And Test Of Ultra-High Efficiency,High Speed Silicon-Based Micro Ring Modulator

With the development of cloud computing and big data,the amount of data transmitted between the chips grows explosively.In comparison with electrical signal propagation,optical propagation has larger bandwidth,much smaller loss and lower consumption.As a result,data transmission between chips will use more optical transmission lines and less copper transmission lines.Due to the transparency in communication band and compatibility with the existing CMOS technology,silicon photonics gradually becomes a new research direction.Of all silicon photonic devices,electro-optic modulator is one of the most important devices.It is of great practical significance to study electro-optical modulation with high modulation efficiency and high speed.This paper proposes a novel electro-optical micro-ring modulator with ultra-high modulation efficiency and high performance based on compressively strained Si Ge and heterotypic PN junction.Through the optimized design,device fabrication,test and verification,based on conventional depletion micro-ring modulator,a strained p-Si Ge epitaxy layer on waveguide will be used to achieve the high modulation efficiency by reducing effective mass of hole and increasing vertical p-Si Ge/n-Si junction area;and an axial wavelike heterotypic PN junction on micro-ring waveguide is designed to enlarge the axial Si-PN junction area and then further improve device modulation efficiency.One step of lithography and metal deposit were used to fabricate both Ti/Ti N/Al electrodes and 50? impedance.The quality of single crystal epitaxy,contact resistance,sheet resistance,50? matching impedance,optical and DC characterization of micro-ring modulator all meet our expectations after testing and analyzing.Finally we tested that the modulation efficiency of traditional micro-ring modulator is 2.24V·cm.And the modulation efficiency of modulators with wave type PN junction and p-Si Ge epitaxial layer are separately 1.88V·cm and 0.74V·cm.The modulation efficiency are promoted and the modulation speed can reach30 Gbps.In summary,the proposed strained p-Si Ge and wave-type PN junction micro-ring resonant modulator are effective methods to achieve high modulation speed and high modulation efficiency.