A defect-oriented test approach using on-Chip current sensors for resistive defects in FinFET SRAMs

Abstract

Resistive defects in FinFET SRAMs are an important challenge for manufacturing test in submicron technologies, as they may cause dynamic faults, which are hard to detect and therefore may increase the number of test escapes. This paper presents a defect-oriented test that uses On-Chip Current Sensors (OCCSs) to detect weak resistive defects by monitoring the current consumption of FinFET SRAM cells. Using OCCSs, all resistive defects injected in single cells considered in this paper have been detected within a certain accuracy by applying 5 read or write operations only, independent whether they cause static or dynamic faults. The proposed approach has been validated and the detection accuracy has been evaluated. Simulation results show that the approach is even able to detect weak resistive defects that do not sensitize faults at the functional level, thus able to increase the reliability of devices.