A unified method for parametric fault characterization of post-bond TSVs

Abstract

A TSV in a 3D IC could suffer from two major types of parametric faults — a resistive open fault, or a leakage fault. Dealing with these parametric faults (which do not destroy the functionality of a TSV completely but only degrade its quality or performance) is often trickier than dealing with a stuck-at fault. Previous works have not proposed a unified test structure and method that can characterize their respective effects. Based on our previous test structure, called VOT (Variable Output Threshold) scheme for delay faults, we propose a unified in-situ characterization flow for both parametric fault types of a post-bond TSV. With this flow, one can easily derive a more insightful assessment of a parametric fault in production test, process monitoring, and/or diagnosis-driven yield learning.