Modeling and Analysis of TSV Noise Coupling Effects on RF LC-VCO and Shielding Structures in 3D IC

Abstract

In this paper, we proposed through silicon via (TSV) to active circuit noise coupling model based on 3-dimensional transmission line matrix method and analyzed the noise coupling paths. When a TSV is located near the active circuit, the noise can easily travel through various coupling paths. With the proposed model, the noise coupling coefficient between TSV and the active circuit in a 3D IC can be estimated precisely. The cross-coupled differential LC-VCO was analyzed as the target active circuit because it is one of the main components in RF applications. With the suggested model, the noise coupling effects from the various coupling paths were compared, and the most critical noise coupling path was determined. We verified the accuracy of the proposed model with full 3D EM simulation results. Additionally, we proposed shielding structures using a guard ring and the ground TSVs for suppression of the noise coupling in 3D IC. The proposed noise suppression methods can reduce the TSV noise by blocking the noise paths to the active circuit. Various shielding structures were evaluated by comparing the different phase noise of LC-VCO to analyze the shielding effectiveness.