Systematic deprocessing: a technique for identification of the origins of process-induced damage and threshold voltage shifts

Back-end plasma process-induced damage has become a major concern for device reliability. Previous methods of process characterization do not allow for isolation of a single process within a metal loop. To solve this problem we developed a deprocessing technique that provides the capability for understanding the impact of a single process on transistor performance and reliability. This deprocessing technique is applied to pinpoint the source(s) of plasma damage. It is also used to identify the impact of backend plasma processes on interfacial Si-H concentration, which reportedly affects negative bias temperature instability lifetimes.