The Study On Design And Automatic Test Method Of Silicon Optical Waveguide Devices

Silicon photonic integrated circuit relies on CMOS process platform and canused microelectronic integrated circuit for reference in design methods,simulationtools and processes flow to a large extent.Therefore,silicon photonic integratedcircuit has developed rapidly in recent years.However,silicon photonic integratedcircuits still different from microelectronic integrated circuit in terms of deviceperformance,layout characteristics and fabrication process.Silicon photonicintegrated circuit is not mature and has to face some bottlenecks in its large-scalemanufacturing.As the interface between silicon photonic integrated circuit andoptical fiber,laser and other chips,grating coupler is one of the important passiveoptical components in silicon photonic integrated circuit.In this dissertation,thegrating coupler is taken as the main research object,and the performanceoptimization scheme is proposed.In addition,aiming at the problem of processtolerance analysis in mass production of silicon photonic wafers,a wafer-levelautomatic characteristic testing and analysis method based on grating coupler isproposed.The main tasks are as follows:An immune particle swarm optimization algorithm for automatic simulation optimization of grating coupler structure is proposed.In the optimization process of grating coupler,this algorithm has better optimization results than the particle swarm optimization algorithm,which is widely used.At the same time,low simulation efficiency and long design cycle can be optimized.Double-layer grating coupler with center wavelength of 1550 nm and 850 nm was designed.The grating coupler needs no special manufacturing process and meets all conditions of mass production process.The simulation results showed that the peak coupling efficiency was 64.8% and 78%,respectively,with excellent performance.The simulation result of the coupling efficiency of the designed grating coupler with the central wavelength of 850 nm is obviously higher than that reported so far.The test results show that the performance of the double-layer grating coupler with a central wavelength of 1550 nm is obviously better than that of the normal uniform grating coupler.Aiming at the structural deviations of silicon photonic waveguide,the silicon grating coupler is used to realize the wafer-level automatic testing.The dimension uniformity of the rib waveguide on 300 mm wafer prepared by 90 nm CMOS process was evaluated based on wafer-level automation testing,and the error of the extraction method was analyzed.The results show that the average processing deviations of rib waveguide width and height are-11 nm and 6nm respectively.The large size deviations of the ridge waveguide are mainly distributed at the edge of the wafer.The extraction error of the rib waveguide size deviation extraction method is on the sub-nanometer scale,and the extraction result is reliable.