Over-erase phenomenon in SONOS-type flash memory and its minimization using a hafnium oxide charge storage Layer

Author

Tan, Yan-Ny ; Chim, Wai-Kin ; Cho, Byung Jin ; Choi, Wee-Kiong

Author_Institution

Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore

Volume

51

Issue

7

fYear

2004

fDate

7/1/2004 12:00:00 AM

Firstpage

1143

Lastpage

1147

Abstract

The over-erase phenomenon in the polysilicon-oxide-silicon nitride-oxide-silicon (SONOS) memory structure is minimized by using hafnium oxide or hafnium aluminum oxide to replace silicon nitride as the charge storage layer (the resulting structures are termed SOHOS devices, where the "H" denotes the high dielectric constant material instead of silicon nitride). Unlike SONOS devices, SOHOS structures show a reduced over-erase phenomenon and self-limiting charge storage behavior under both erase and program operations. These are attributed to the differences in band offset and the crystallinity of the charge storage layer.

Keywords

hot carriers; leakage currents; semiconductor device models; thin film transistors; 2D numerical simulation; AF-TFT; device structures; kink effect suppression; leakage current; n region; polycrystalline silicon; polysilicon thin-film transistors; series resistance; transistor channel region; Aluminum oxide; Crystalline materials; Crystallization; Dielectric materials; Flash memory; Hafnium oxide; High-K gate dielectrics; Material storage; SONOS devices; Silicon; Flash memories; SONOS; hafnium aluminum oxide; hafnium oxide; high dielectric constant; high-$kappa$; over-erase; polysilicon–oxide–silicon nitride–oxide–silicon;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2004.829861

Filename

1308639