In-situ method for TSV delay testing and characterization using input sensitivity analysis

In this paper, we propose a method and the required architecture for characterizing the propagation delays of the through Silicon vias (TSVs) in a 3-D IC. First of all, every two TSVs are paired up to form an oscillation ring with some peripheral circuits. Their joint performance can thus be measured roughly by the oscillation period of the ring. Next, we utilize a technique called sensitivity analysis to further derive the propagation delay of each individual TSV participating in an oscillation ring--a distilling process. In this process, we perturb the strength of the two TSV drivers, and then measure their effects in terms of the change of the oscillation ring's period. By some following analysis, the propagation delay of each TSV can be revealed. On top of scheme, we also present an architecture that can activate the performance characterization process of each test unit--that consists of two TSVs--one at a time in a proper sequence. The area overhead is only 18.97 equivalent two-input NAND gate per TSV, by which one can gain the ability to profile the capacitances and the propagation delays of the TSVs on a 3-D IC.