Design And Analysis Of Optoelectronic Interconnection Micro-nano System On All-silicon Chip

The semiconductor industry is booming,and various high-performance chips are developing with each passing day in terms of chip design.Due to the objective physical characteristics,the slowdown in the advancement of integration restricts the circuit performance of the chip to a certain extent.The traditional silicon chip circuit uses the physical pattern structure formed by etching to realize the interconnection of electrical signals.Under the condition that the shrinking size of the etched pattern is slowing down,a new on-chip interconnection method optical interconnection,under the same integration density,can provide wider communication bandwidth,preciser signal and faster signal processing speed.At the same time,the on-chip optoelectronic interconnection can realize the mutual communication of optoelectronic systems and realize the multi-functional on-chip micro-nano system.The research on all-silicon optical interconnection is the basis for further realizing the interconnection of optoelectronic systems.Traditional photonic devices are designed on the basis of III-V materials,but the hetero-integration of III-V materials with silicon materials faces huge design challenges and high costs.Traditional large-scale integrated silicon chips are generally fabricated using standard complementary metal-oxide-semiconductor(CMOS)processes.To achieve on-chip optoelectronic interconnection,it is necessary to realize silicon light source devices compatible with CMOS processes,waveguide structures for coupling and transmission of light,and a detection device that detects light at the end of the waveguides.In view of the characteristics of silicon as an indirect band gap semiconductor material,it is the key and difficult to fabricate practical silicon optical devices with high electro-optical conversion efficiency on all-silicon wafers.At the same time,it is necessary to design a silicon waveguide structure with low propagation loss,so as to meet the basic requirements for the realization of optoelectronic interconnection systems.In this thesis,aiming at the basic realization requirements of photoelectric interconnection micro-nano system,the structure design of photoelectric devices based on all silicon,the principle of electron conversion into photon excitation,the combination and comparison of special waveguide coupling structure,and the conduction efficiency under different waveguide orbit changing patterns to realize non-linear light conduction are studied.The silicon optical device is a polycrystalline silicon device with N⁺-P-N⁺-P-N⁺cascade structure with heavily doped N region.By applying reverse bias voltage at both ends of the device,the two N⁺-P regions in the device can produce reverse avalanche breakdown to achieve luminescence.The external quantum efficiency of the silicon optical device is 2.9×10^-7 and the electro-optical conversion efficiency is 2.2×10^-8 by means of carrier injection effect.The silicon on insulator(SOI)structure is used in the design of the silicon optical device,and the top of the device has a silicon dioxide protective layer,so the coupling of silicon dioxide and waveguide material should be considered in the study of the waveguide.In the waveguide simulation,the waveguide light conduction efficiency without rectangular grating is compared with the periodic rectangular grating with different sizes(the periods of the rectangular grating are 0.05?m,0.1?m,0.2?m,0.4?m,0.6?m,0.8?m and 1?m,respectively).For TE mode and TM mode,when the duty ratio of the rectangular grating is 0.5,the waveguide with grating period of 0.2?m has the best transmittance,and the continuous reduction of the rectangular grating period will not improve the transmittance.In addition,different grating depths(0.025?m,0.05?m,0.1?m,0.2?m,0.3?m and 0.4?m)were designed and simulated under the condition that the period of the rectangular grating was set at 0.2?m.It is concluded that the optimum transmittance of TE mode and rectangular grating depth is 99.361%and 96.715%,respectively,in the case of perpendicular incidence.However,after comprehensively considering the characteristics of scattered light sources,the optimal grating depth in TE mode is 0.3?m,and the optimal grating depth in TM mode is 0.4?m.Based on the coupling of a rectangular grating with a period of 0.2?m and a depth of 0.3?m,the two-stage declination track change of the waveguide was designed and simulated.The deflection angles were set as 7.5°,15°,22.5°,30°,37.5°,45°,52.5°and 60°,respectively.For TE mode radiation with incident angle less than 22.5 deg,the comprehensive transmittance of the waveguide at 7.5°is higher than that at 15°.For the TM mode radiation with an incident angle less than 25 deg,the comprehensive transmittance of the waveguide at 7.5° is higher than that at 15°.