Threshold Voltage Variability of NROM Memories After Exposure to Ionizing Radiation

Author

Corso, Domenico ; Libertino, Sebania ; Lisiansky, Michael ; Roizin, Yakov ; Palumbo, Felix ; Principato, Fabio ; Pace, Calogero ; Finocchiaro, Paolo ; Lombardo, Salvatore A.

Author_Institution

Ist. per la Microelettron. e Microsist. (IMM), Catania, Italy

Volume

59

Issue

10

fYear

2012

Firstpage

2597

Lastpage

2602

Abstract

Threshold voltage (V_th) behavior of nitride read-only memories (NROMs) was studied after irradiation with photons (γ- and X-rays), light and heavy ions. Both programmed and nonprogrammed single cells were investigated. The data suggest that two main physical phenomena are contributing to V_th variation and that the V_th loss and the variability can be modeled by a Weibull statistics with a shape parameter k ~ 2.2 regardless of the irradiation species and total dose. The same peculiarities were found in large memory arrays, confirming the results from single-cell studies but with significantly larger statistics. Hence, once the irradiation dose is known, the V_th loss distribution can be obtained, thus providing a predictive model of the radiation tolerance of NROM memory arrays.

Keywords

Weibull distribution; nitrogen; photons; radiation effects; read-only storage; N; NROM memory array; Weibull statistics; heavy ion; ionizing radiation; light ion; nitride read-only memory array; nonprogrammed single cell; photon irradiation dose; programmed single cell; shape parameter; single-cell study; threshold voltage variability; Dielectrics; Electron traps; Ionizing radiation; Logic gates; Nonvolatile memory; Radiation effects; Flash memories; nitride read-only memories (NROMs); oxide–nitride–oxide (ONO); radiation hardness;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2012.2206596

Filename

6287009