High-quality pattern selection for screening small-delay defects considering process variations and crosstalk

Testing for small-delay defects (SDDs) is necessary to ensure the quality and reliability of high-performance integrated circuits fabricated with the latest technologies. These timing defects can be caused by process variations, crosstalk, and power-supply noise, as well as by physical defects such as resistive opens and shorts. Timing-aware ATPG tools have been developed for SDD detection. However, they only use static timing analysis reports for path-length calculation and neglect important parameters such as process variations, crosstalk, and power-supply noise, which can induce small delays into the circuit and impact the timing of targeted paths. In this paper, we present an efficient pattern evaluation and selection procedure for screening SDDs that are caused by physical defects and by delays added to paths by process variations and crosstalk. In this procedure, the best patterns for SDDs are selected from a large repository test set. Experimental results demonstrate that our method sensitizes more long paths and detects more SDDs with a much smaller pattern count compared with a commercial timing-aware ATPG tool.