Time Dependent Breakdown of Ultra-Thin Gate Dielectrics Under Pulsed Biased Stress

Published

March 1, 2001

Author(s)

Bin Wang, John S. Suehle, Eric M. Vogel, J B. Bernstein

Abstract

Ultra-thin SiO₂ films (t_ox 2.0 nm) were stressed under DC, unipolar, and bipolar pulsed bias conditions up to a pulse repetition frequency of 50 kHz. The time-to-breakdown (t_BD), the number of defects at breakdown (N^dBD), and the number of defects generated inside the oxide as a function of stress time were monitored during each stress dondition. Oxide lifetime under unipolar pulsed bias is similar to that under DC conditions; however lifetime under bipolar pulsed bias is significantly improved and exhibits a dependence on pulse repetition frequency. The observation of a lifetime increase under bipolar pulsed bias for the oxide thickness and voltage range used in this study suggests that a different physical mechanism may be responsible for the lifetime increase from that assumed in earlier studies for thicker films.

Citation

IEEE Electron Device Letters

Volume

22

Issue

5

Pub Type

Journals

Keywords

dielectric breakdown, reliability, silicone dioxide, ultra-thin gate dielectric

Citation

Wang, B. , Suehle, J. , Vogel, E. and Bernstein, J. (2001), Time Dependent Breakdown of Ultra-Thin Gate Dielectrics Under Pulsed Biased Stress, IEEE Electron Device Letters (Accessed March 13, 2025)