Study On TSV Coupling Crosstalk And Its Optimization

As the feature size of integrated circuits continues to decrease and the degree of integration is greatly improved,the problem of restricting the development of two-dimensional integrated circuits has become increasingly prominent.However,the three-dimensional integration technology based on through silicon vias(TSV)provides new ideas for the development of integrated circuits.The chips are stacked in the vertical direction through TSV interconnection lines,which greatly reduces the length of interconnection lines,signal delay and improves system integration.However,while the TSV-based three-dimensional integration technology brings many advantages,the problem of coupling crosstalk between TSV interconnect lines has become increasingly severe,which seriously affects the signal transmission quality,and even causes the circuit to not to function properly.Therefore,it is extremely urgent to study the coupling crosstalk problem.Aiming at the problem of coupling crosstalk between TSV interconnect lines,this paper proposes a new coaxial double ring TSV structure,which conducts in-depth research on TSV transmission characteristics,coupling crosstalk between TSV interconnect lines,and ways to optimize crosstalk in the array.,The main work are listed as follows:Firstly,a new type of coaxial double ring TSV structure is proposed,and its ?-type equivalent circuit model is established.Compared with the HFSS simulation results,it fits well in a wide frequency range and verifies the correctness of the equivalent circuit model.The single variable method is used to scan and analyze the structural parameters such as the height of the coaxial double ring TSV,the thickness of the inner and outer copper rings,the thickness of the BCB dielectric layer,the conductivity of the substrate,and the material of the dielectric layer.The effect of the structural parameters on the transmission characteristics are compared and analyzed.The delay and characteristic impedance of the coaxial double ring TSV interconnection line are analyzed by TDR/TDT.The results show that the TSV delay of this structure is almost zero,and its characteristic impedance is stable and continuous.At last,the process flow of the proposed coaxial double ring TSV structure is given.Secondly,the study analyzed the advantages of coaxial double ring TSV in reducing crosstalk.Compared with the traditional TSV structure and the derivative structure of coaxial TSV with benzocyclobutene(BCB)as the dielectric layer,the coupling crosstalk is reduced by 99 d B from 0 to 100 GHz.The result shows that it has better anti-interference ability.In the frequency domain,the influence of coaxial double ring TSV on crosstalk noise when different structural parameters changing are analyzed.The results show that reducing TSV height,substrate conductivity and increasing TSV spacing can effectively reduce the coupling crosstalk between interconnections.The influence of rise time and frequency of signal on TSV crosstalk noise is analyzed in the time domain.The results show that the shorter the rise time,the greater the crosstalk noise and the obvious changes,while the signal frequency has little effect on the crosstalk.Finally,the improvement degree of the crosstalk between the signals of the TSV array under different optimization methods is studied.The results show that for the traditional TSV structure,when the signal and the ground TSV are arranged staggered,the coupling crosstalk can be reduced,but the crosstalk suppression ability is limited.The coaxial double ring TSV can greatly reduce the crosstalk between signals,and more TSVs can be arranged on the same area of the substrate.