Modeling and analysis of LC-VCO performance degradation and shielding for tsv noise coupling in 3D IC

Abstract

As demands for the small form factor, wide bandwidth, high performance, and low power consump-tion have become greater in number, through silicon via (TSV) based 3-dimensional integrated circuit (3D IC) is expected to be the key to the solution of next generation technology. One of the most significant issues in 3D IC is noise coupling problem. As various function of ICs such as digital core, RF, and memory are combined with TSV for 3D IC, TSV noise can be easily coupled to near ICs. Especially, highly sensitive RF/analog components like LC-VCO can be strongly affected by TSV cou-pling noise through various paths. As a result, performance of RF circuit can be degraded. Many studies have focused on estimation of noise coupling coefficient. However the previous studies only consider TSV to TSV or TSV to contact coupling, and there is lack of research on TSV to active circuit noise coupling. In this thesis, noise coupling between TSV and LC-VCO which is targeted active circuit is analyzed. 5 paths of TSV to LC-VCO noise coupling are determined, and model of each path is proposed by 3D-TLM method. From the model, the voltage transfer function as the coupling coefficient is obtained. Then TSV noise coupling mechanism of each path is analyzed under several parameter variations The Model was veri-fied by 3D EM solver simulation. Noise coupling effect on LC VCO phase noise is investigated in each coupling path. Results of 5 noise coupling paths are compared, and the critical path is determined. After analysis of LC-VCO performance degradation due to TSV noise coupling, several shielding methods are proposed for noise suppression. Com-paring with each other, shielding methods are applied for improving performance of LC-VCO.