US Patent 7898277 Hot-electronic injection testing of transistors on a wafer

A hot-carrier injection (HCI) test that permits rapid screening of integrated circuit wafers susceptible to possible HCI-induced failures is disclosed. A method is described that determines transistor stress voltages that results in a transistor HCI-induced post-stress drain current differing from a pre-stress drain current within a desired range. These stress voltages are determined using a wafer with acceptable HCI susceptibility. Additional wafers to be tested are first tested using a described method that uses the determined transistor stress voltages to quickly screen the wafers for HCI susceptibility and, if HCI susceptibility is found, then additional conventional HCI testing may be applied to the susceptible wafers.