Back-End-of-Line Defect Analysis for Rnv8T Nonvolatile SRAM

Rnv8T nonvolatile SRAM combines conventional SRAM and resistive RAM to provide both fast access speed and data retention. Traditional test methods for conventional SRAM or resistive RAM are not suitable for nonvolatile SRAM. This paper analyzes the defective behavior of the Rnv8T nonvolatile SRAM based on defect injection and simulation. Simulation results showed that the inject defects caused stuck-at faults and transition faults which escaped from conventional March tests. Based-on the defective behavior and circuit operations, a straight forward test algorithm is proposed to detect the escaped faults.