Resolving systematic voltage sensitive soft failures in 28nm microprocessor devices

With rapid developments in semiconductor manufacturing technologies, new and more complicated challenges emerge in the Failure Analysis space. It has been a challenge to perform failure analysis for voltage-sensitive soft failures, especially those occurring in SRAM circuitries. However, fault localization in sub-micron devices is successful if existing FA techniques are innovatively and extensively leveraged during physical fault isolation. This paper emphasizes the use of SEM-based nano-probing followed by advanced TEM techniques to successfully identify the root cause of failure, thus enabling the wafer fab to take appropriate corrective measures to mitigate such failures. A successful case study involving these techniques will also be discussed.