Case History: Passive Voltage Contrast Technique for In-Line Characterization and Failure Isolation During Development of Deep-Submicron ASIC CMOS

Abstract

Abstract Passive voltage contrast (PVC) has traditionally been used by semiconductor engineers for end-of-line post-mortem analysis. PVC distinguishes between open and short structures and is both nondestructive and noncontact. When applied during process development for in-line characterization, it allows wafers to be examined at multiple points, where electrical probing might not be feasible. This provides feedback on the cumulative effect of the process on critical parameters such as oxide integrity and can reduce development cycle times because wafers do not have to be deprocessed in order to determine the exact location of failures. Two case studies are presented in this article, demonstrating the use of PVC in a process development environment.