Modeling,Design And Optimization Of Differential Transmission Structure In 3-D ICs

“There's a law about Moore's Law,” jokes Peter Lee,a vice-president at Microsoft Research: “The number of people predicting the death of Moore's Law doubles every two years.” Since the 21 th century,there are a bunch of innovative technologies flourish with the explosive development of planner integrated circuits.The emerging fields including big data,artificial intelligence and virtual reality have being proposed higher demand for ultrahigh-speed supercomputing systems.The through-slicon via(TSV)based three-dimentional integrated circuit(3D IC)has been invented and further developed to meet these harsh requirements.In compression with conventional planer integrated circuits,the TSV-based 3-D ICs have various advantages,including higher integration density,shorter interconnect length,better noise immunity,lower power consumption,and faster data communication.More importantly,the heterogeneous integration of multi-chip modules(e.g.,sensors,memory,logic,and radio frequency circuits)becomes possible through the TSV techniques.However,just like a rose has its thorns,there are several challenges in the real-world applications of TSVs.As the operating frequency increases,the noise coupling among devices will introduce some electromagnetic interference and signal integrity problems.And the inherent frequency-dependent loss of the silicon substrate will limit the high-speed data transmission and results in degradation of the channel bandwidth.Therefore,this dissertation is focused on the signal integrity analysis of TSV based 3D ICs.The modelling and optimization of TSV based differential transmission channels has been employed to improve the quality of high-speed digital signals in 3D ICs.This dissertation can be divided into the following three parts:In the first part,the equivalent circuit models of three types of differential transmission channels(including ground-signal-signal-ground type TSVs,on-chip differential interconnects and the whole structure combined both of the vertical and lateral transmission structures)have been proposed and analyzed.Further,the simplified models of these three types of structures are derived from the above metioned equivalent circuit models.The simplified models only contain several frequencyindependent components and can accurately predict differential-mode insertion loss Sdd21 from DC to 20 GHz.The second part of this dissertation is dedicated to solve the inherent insertion loss problems caused by the semiconducting silicon substrate when differential signals are transmitted through TSVs and on-chip interconnects.Based on the above mentioned simplified circuit models,the passive equalizers are designed based on system transfer functions.And in order to come up with the “over-comsumption” problems caused by the low-loss properties of on-chip interconnects,the nter-symbleinterference(ISI)cancellation algorithm are proposed to calculated the optimial electrical parameters of passive equalizers for a given transmission channels.The third part is mainly focused on the study of the crosstalk problems of the conventional differential transmission channels.The complex electromagnetic environment in 3D ICs causes differential transmission channels suffer some inevitable external interferences and couplin noises which will seriously degrade the quality of high-speed differential signals.Therefore,a shield differential annular through-silicon via(SD-ATSV)is proposed and investigated.Firstly,the thermomechanical stress of the SD-ATSV is captured and compared with that of the shielded-differential cylindrical through-silicon via.Then,the equivalent circuit model is developed with the influence of the electrically floating silicon substrate taken into account.By virtue of the circuit model,the frequency-and time-domain electrical characterizations of the SD-ATSV are conducted.Finally,a parallel resistor–capacitor passive equalizer which achieves wide-band equalization and perfect compensation for high-speed differential signalling is proposed and designed based on the system transfer function.In brief,this dissertation focuses on the modelling and optimization of differential transmission structure in 3-D ICs.The modeling and perfoemance analysis of differential transmission channels are performed and the crosstalk and inherent substrate loss problems are analysed and solved.