Performance and reliability optimizations of BE-SONOS NAND Flash using SiON bandgap-tuning tunneling barrier

Author

Liao, Jeng-Hwa ; Hsieh, Jung-Yu ; Lue, Hang-Ting ; Yang, Ling-Wu ; Yang, Tahone ; Chen, Kuang-Chao ; Lu, Chih Yuan

Author_Institution

Technol. Dev. Center, Macronix Int. Co. Ltd., Hsinchu, Taiwan

fYear

2010

fDate

2-6 May 2010

Firstpage

639

Lastpage

643

Abstract

Bandgap-tunable SiON (oxynitride) tunnel barrier is developed to optimize the performance and reliability of BE-SONOS NAND Flash devices. The HTO O2 layer of the ONO tunnel barrier is replaced by SiON thin films with various refractive index (n) and thickness. We found that with n ≤ 1.72, SiON can provide excellent data retention comparable to conventional BE-SONOS. On the other hand, the erase speed can be greatly improved by using SiON O₂ when n > 1.50. We suggest that hole barrier lowering by SiON is the root cause of such erase speed improvement. Our results suggest an optimal 35 Å SiON O2 layer with n = 1.63 for the best program/erase speed and data retention performance. Finally, a 75 nm BE-SONOS NAND device is fabricated to validate the performances of this concept.

Keywords

NAND circuits; circuit optimisation; flash memories; integrated circuit reliability; silicon compounds; tunnelling; BE-SONOS NAND Flash reliability optimizations; HTO; SiON; SiON bandgap-tuning tunneling barrier; data retention; hole barrier; refractive index; size 75 nm; Dielectric constant; Dielectric materials; Optical films; Optical refraction; Oxidation; Refractive index; Stimulated emission; Thermal engineering; Transistors; Tunneling;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium (IRPS), 2010 IEEE International

Conference_Location

Anaheim, CA

ISSN

1541-7026

Print_ISBN

978-1-4244-5430-3

Type

conf

DOI

10.1109/IRPS.2010.5488756

Filename

5488756