Electrical analysis of TSV step change in radius with compensation structure

Abstract

Through silicon via (TSV) is a key technology in 3-D integrated circuits (3-D ICs). At the junction of TSV and pad, an extra loss produced by the discontinuous structure is inevitable in microwave circuit, and it can not be ignored. A compensation structure which can compensate the loss from step change in radius is proposed in this paper. The conventional structure and compensation structure are simulated by High Frequency Structure Simulator (HFSS). Simulation result shows that the proposed compensation structure can effectively reduce the return loss within the whole frequency range, and the compensation of insertion loss is more obvious at higher frequency. A series of top layer compensation structures with different diameter ratios are simulated. The simulation result shows that the larger the diameter ratio, the more obvious the compensation is. As the analysis based on the impedance model of TSV correlates well with the simulations, the proposed compensation structure is a worthwhile guideline for the design of 3-D ICs.