Effects of front-end-of line process variations and defects on retention failure of flash memory: Charge loss/gain mechanism

Author

Jongwoo Park ; Miji Lee ; Hanbyul Kang ; Wooram Ko ; Eunkyeong Choi ; Junsik Im ; Minwoo Lee ; Dohwan Chung ; Jinchul Park ; Sangchul Shin ; Sangwoo Pae

Author_Institution

Syst. LSI Bus., Samsung Electron. Co., Ltd., Yongin, South Korea

fYear

2015

fDate

19-23 April 2015

Abstract

Retention fails on flash memory were comprehensively characterized and fault-isolated for the formulation of failure mechanism. Using in-depth TEM and SIMS characterizations based on electrical findings, we found that FEOL process variations such as contact misalignment (spacer encroachment) and defects (ONO instability and stacking fault), result in retention fail of flash memory. In this paper, the failure mechanism of retention fail governed by charge loss/gain in a same cell is explicated and knobs for robust reliability and decent production are proposed from design and process perspectives.

Keywords

circuit reliability; failure analysis; fault diagnosis; flash memories; secondary ion mass spectra; secondary ion mass spectroscopy; transmission electron microscopy; FEOL process variation; ONO instability; SIMS characterization; TEM; charge loss-gain mechanism; contact misalignment; failure mechanism; flash memory; front-end-of line process variation; reliability; retention failure; spacer encroachment; stacking fault-isolation; Failure analysis; Flash memories; Ions; Mobile communication; Passivation; Silicon compounds; Stacking; As+ implantation; Front-end-of line (FEOL); SIMS; TEM; charge loss/gain; contact misalignment; dislocation; mobile ion; oxygen-nitride-oxygen (ONO) layer; retention fail; stacking fault;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium (IRPS), 2015 IEEE International

Conference_Location

Monterey, CA

Type

conf

DOI

10.1109/IRPS.2015.7112674

Filename

7112674