IR-Drop Analysis of Hybrid Bonded 3D-ICs with Backside Power Delivery and mu- & n- TSVs

Abstract

We present an IR-drop analysis of hybrid bonded 3D-ICs Power Delivery Network with backside metals and buried power rail. Two different options for the backside to frontside connectivity are included: mu TSVs and nTSVs (respectively 0.5 mu m, 0.09 mu m diameter and 1 Omega, 10 Omega nominal resistance). Further, Hybrid Bonding CuPads are used to deliver power to the second die in the stack. A commercial power analysis tool is extended to support both the TSV and the pads structures, to tackle both inter-die and on-die power delivery challenges. A L1 cache memory implemented on the top of a core is used as test case to assess the performance of the proposed metal stack. A 69% reduction in average static IR-drop is observed with the BS-PDN compared to the conventional frontside. Further, 81% and 77% average and peak IR-drop reductions are obtained with nTSV compared to mu TSV.