An enhanced time-to-digital conversion solution for pre-bond TSV dual faults testing

Abstract

Pre-bond TSV test plays a vital role in improving the yield and reducing the cost of 3D ICs. In this paper, a non-invasive solution for pre-bond TSV test based on pulse shrinking is proposed. This method makes use of the fact that defects in TSV lead to variation in the propagation delay - the rise and fall times are first transformed into pulse width, and the pulse shrinking technique is used to digitize the pulse width into a digital code which is then compared with an expected value for a fault-free TSV. Experiments on TSV defect detection are carried out using HSPICE simulations with realistic models for 45 nm CMOS technology. Experimental results show that the proposed method can detect not only open (leakage) fault but also dual faults with high resolution.