Research On Wide Band Modeling Of Air GAP Coaxial TSV(CTSV)

With the development of semiconductor technology,the bottleneck encountered is more and more difficult to overcome,and the problems caused by the short channel effect and carrier speed saturation are more and more obvious.Three-Dimension Integrated Circuit?3D IC?technology can stack multiple chips with different functions together and connect multiple devices by using Through-Silicon Via?TSV?,which effectively reduces the interconnect length and enables heterogeneous chip integration.TSV is a key factor in semiconductor 3D integration technology,and its working frequency is diversified.Therefore,it is of great significance to study the wide-band characteristic of TSV.In this paper,the air-gap coaxial TSV is deeply studied.After considering the effects of Metal-Insulator-Semiconductor?MIS?structure,substrate eddy current loss and current skin effect,the parasitic parameters of this structure are obtained and the equivalent circuit is established.Comparing this model with the HFSS software simulation curves,the results shows that the error of return loss S₁₁ and insertion loss S₂₁ is within 5%,which verifies the correctness of the model in wide band.The model can simulate transmission from 100MHz to 100GHz and has a wide range of applications.The exact TSV capacitance under the non-depletion layer approximation is studied.The comparison shows that the actual TSV capacitance differs from the depletion layer approximation by 10%.Applying this result to the model can further improve the accuracy of the model.Based on the above mentioned research,the control parameters method is used to study the structural parameters and doping concentration of the model.The transmission parameters under different models are compared and analyzed.The results show that the TSV height and the number of air gaps have the greatest influence on the transmission characteristics.The original TSV structure is optimized.At 100 GHz,the return loss S₁₁ is-15dB and-30dB before and after optimization,and the insertion loss S₂₁ is-0.26dB and-0.03dB before and after optimization.The optimized TSV has a smaller reflection coefficient and a higher transmission coefficient,and the transmission characteristics are more than doubled.According to the characteristics of the process,the structure and transmission characteristics of the conical air-gap coaxial TSV are studied.The simulation shows that the transmission characteristics of the vertical structure TSV are better than that of the cone structure under the same size.The difference between the two structures is large in the low frequency band and smaller in the middle and high frequency.The effects of TSV height,sidewall inclination,temperature,and substrate dielectric materials on the transmission characteristics are investigated.The results show that the type of substrate dielectric has the greatest influence on the transmission characteristics.At 100 GHz,the return loss S₁₁ is-14 dB and-22 dB before and after optimization,and the insertion loss S₂₁ is-0.31 dB and-0.1 dB before and after transmission,and the transmission characteristics become better.