Single event effects induced by heavy ions in SONOS charge trapping memory arrays

T. Patrick Xiao, Christopher H. Bennett, Sapan Agarwal, David R. Hughart, Hugh J. Barnaby, Helmut Puchner, A. Alec Talin, Matthew J. Marinella

Research output: Contribution to journalArticlepeer-review


We investigate the sensitivity of silicon-oxide-nitride-silicon-oxide (SONOS) charge trapping memory technology to heavy-ion induced single event effects. Threshold voltage (VT) statistics were collected across multiple test chips that contained in total 18 Mbit of 40-nm SONOS memory arrays. The arrays were irradiated with Kr and Ar ion beams, and the changes in their VT distributions were analyzed as a function of linear energy transfer (LET), beam fluence, and operating temperature. We observe that heavy ion irradiation induces a tail of disturbed devices in the ‘program’ state distribution, which has also been seen in the response of floating-gate (FG) flash cells. However, the VT distribution of SONOS cells lacks a distinct secondary peak, which is generally attributed to direct ion strikes to the gate stack of FG cells. This property, combined with the observed change in the VT distribution with LET, suggests that SONOS cells are not particularly sensitive to direct ion strikes but cells in the proximity of an ion’s absorption can still experience a VT shift. These results shed new light on the physical mechanisms underlying the VT shift induced by a single heavy ion in scaled charge trap memory.

Original languageEnglish (US)
JournalIEEE Transactions on Nuclear Science
StateAccepted/In press - 2021
Externally publishedYes


  • Charge trap memory
  • flash memory
  • heavy ion irradiation
  • Ion beams
  • Ions
  • Logic gates
  • Nonvolatile memory
  • Radiation effects
  • single event effects
  • single event upset
  • SONOS devices
  • Transistors

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


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