Detailed observation of small leak current in flash memories with thin tunnel oxides

Author

Manabe, Yukiko ; Okuyama, Kousuke ; Kubota, Katsuhiko ; Nozoe, Atsushi ; Karashima, Tetsuji ; Ujiie, Kazuaki ; Kanno, Hiroyuki ; Nakashima, Moriyoshi ; Ajika, Natsuo

Author_Institution

Device Dev. Center, Hitachi Ltd., Tokyo, Japan

Volume

12

Issue

2

fYear

1999

fDate

5/1/1999 12:00:00 AM

Firstpage

170

Lastpage

174

Abstract

This paper describes a method for measuring the small current through the oxides on the order of 10^-20 A or less using a floating gate MOSFET and the application results on flash memories with thin tunnel oxides. The method is based on an accurate measurement of the threshold voltage of a floating gate MOSFET with no charge in the floating gate. We applied this method to flash memories to investigate the leak current behavior through thin tunnel oxides with very small areas (<0.16 μm²), and found some anomalous phenomena which cannot be observed from SILC measurements if we use large capacitors. We also discuss possible mechanisms to explain the phenomena

Keywords

MOSFET; electric current measurement; flash memories; integrated circuit measurement; leakage currents; tunnelling; UV irradiation; charge-up; flash memory; floating gate MOSFET; leak current measurement; threshold voltage; tunnel oxide; Capacitance; Capacitors; Current measurement; Dielectric measurements; Flash memory; Flash memory cells; MOSFET circuits; Nonvolatile memory; Threshold voltage; Voltage measurement;

fLanguage

English

Journal_Title

Semiconductor Manufacturing, IEEE Transactions on

Publisher

ieee

ISSN

0894-6507

Type

jour

DOI

10.1109/66.762874

Filename

762874