Purpose
Laser induced timing perturbation can speed-up or slow down transitions either from 1 to 0 (VDD to VSS) or from 0 to 1 (VSS to VDD). Knowledge of the physics behind those effects will help the designer or failure analyst to resolve timing issues. Unfortunately, timing perturbation measurements are often difficult to perform with suitable accuracy. In this paper we present a new technique, Phase Variation Mapping (PVM), which overcomes measurement accuracy issues. The measurement is based on a phase sensitive detector which provides an analog output representation of the laser induced timing variation. PVM belongs to a broader class of variation mappings techniques (which we refer to as ‘xVM’) aimed at solving a variety of marginality-related IC issues.