Total Ionizing Dose Influence on the Single-Event Multiple-Cell Upsets in 65-nm 6-T SRAM

We investigated the total ionizing dose (TID) influence on the single-event multiple-cell upsets (MCUs) in 65-nm 6-T static random-access memory and found that MCU sensitivity of the device is enhanced by TID. MCU caused by particle strike in pMOSFET (p-hits) or nMOSFET (n-hits) is distinguished by the MCU pattern. Analysis of MCU pattern shows that both p-hits MCU and n-hits MCU are enhanced by TID, and they have different mechanisms. Enhancement of n-hits MCU is due to the positive threshold voltage shift (
$\Delta V$
th) of the pull-up pMOSFET, while p-hits MCU is strengthened by the increase in the equivalent resistance of p-well contacts caused by oxide-trapped charges (Not) trapped in the shallow trench isolation.