Abstract
A clock network in a 3D-IC is not only difficult to design, but also challenging to test. For high-performance designs with a rigorous clock-skew requirement, studies have shown that small defects in a clock tree network could lead to unexpected failures in the field and thus need to be identified during the manufacturing test. In this paper, we present a novel test method to determine if a clock network has any small delay faults. This method does not require any change of the clock network, and it is capable of detecting a delay fault as small as 50ps through outlier analysis, while locating the FFs affected by the fault.