Missing Material Defect Analysis And Design Optimization Of Heating Interconnects In Thermo-Optic Devices

With the development of metal thin film preparation technology and polymer materials science,the thermo-optic devices have attracted much attention due to their unique working principle and many advantages.However,due to the miniaturization and integration of the device,the size of the thermo-optic device heating interconnect has reached the nanometer level,increasing the difficulty of the manufacturing process and the probability of the occurrence of defects,which greatly affects the reliability of the device.Based on the working principle of thermo-optic devices,aiming at the weak link of device failure — heating interconnection,combined with theoretical research,simulation analysis and test results,the effects of missing material defects on the life of the interconnects and the performance of the devices were investigated.In addition,for the situation that the Fiber Channel and interconnects continue to increase,the interaction between multiple interconnects was explored and optimization advice is presented.Firstly,combined with the working environment of thermo-optic devices,based on fault physics and experimental study,the failure mechanism is the common action of the multi-physics field dominated by electromigration.The influence of missing material defects on various migration mechanisms in multi-physics field was analyzed by using electromigration theory,as well as the relationship between the life of the interconnect and the failure position to provid the basis for the next simulation model and experimental design.Secondly,according to the theoretical research,the interconnection working mode of the missing material defects with silicon as the substrate was established by ANSYS finite element simulation software.Through the thermo-electric coupling simulation results,the current density,temperature and temperature gradient distributions were obtained.Compared with the parameters of the intact interconnection,the relationship between the size and the position of missing material defects and the life and failure position of the interconnect was clarified.In addition,according to the actual structure of the thermo-optic devices,the temperature distribution of the polymer optical waveguide was analyzed when there was a missing material defect in the heating interconnection,as well as the interaction between multiple interconnects.The simulation results shown as follow: missing material defect has a great influence on the life of the interconnect and the performance of the device;the smaller the interconnection distance,the stronger the interaction;the interaction and the size of the device can be effectively improved by adding insulation material to polymer optical waveguides.Finally,the interconnection test samples were prepared,the samples were observed by light microscopy and other equipments,and the sample defect types were classified.Accelerated life test was carried out for samples with missing material defects.The test results were summaried as follow:(1)When there was a missing material on the interconnect has a defective defect,the failure position is also there;(2)The greater the missing material defect,the shorter the life span;(3)For a certain depth of the scratch defects,failure is caused by electromigration;over a certain range,the failure is caused by over electrical stress.