Diagnosis of Transistor Shorts in Logic Test Environment

For deep-sub micron technology based LSIs, conventional stuck-at fault model is no longer sufficient for fault test and diagnosis. This paper presents a method of fault diagnosis for transistor shorts in combinational and full-scan circuits under logic test environment. Description of a short requires a very large number of physical parameters, and hence it is difficult, if not impossible, to describe precisely the behavior of transistor shorts. Therefore, two types of transistor short models were defined and algorithms to address the diagnostic problem were developed. The novelty of the algorithms is that they use conventional stuck-at fault simulation methodologies to diagnose transistor level shorts. Experiments were conducted on benchmark circuits to demonstrate the effectiveness of the method