Diagnosing the root cause of a failure is particularly challenging if the symptom of the failure is not consistently observable. This article focuses on Laser Assisted Device Alteration/Soft Defect Localization (LADA/SDL), a global fault isolation technique, for detecting such failures. The discussion begins with a section describing the three steps in LADA/SDL analysis setup: create the test loop with the fail flag and loop trigger, select the laser dwell time, and select the shmoo bias point. An overview of LADA/SDL workflow is then presented followed by a brief section on time-resolved LADA. The closing pages of the article consider in detail SDL laser interaction physics and LADA laser interaction physics.
This article addresses the ancillary issues regarding the nanoprobing and characterization of transistors, probing copper metallization layers, and the various imaging techniques. The discussion includes several characterization examples of known transistor failure types, namely four probe transistor characterization, two probe transistor characterization, and probing and characterizing metallization issues. The imaging techniques discussed are those that are specific to atomic force nanoprober or scanning electron microscope based tools. They are current contrast imaging, scanning capacitance imaging, e-beam absorbed current imaging, e-beam induced current imaging, e-beam induced resistance change imaging, and active voltage contrast imaging.