Switching Behaviour and Noise of Soft Breakdown Current in Ultra-Thin Gate Oxides

Abstract

We studied the Soft Breakdown (SB) in ultra-thin gate oxides (< 3 nm) subjected to Constant Current Stress. SB current derives from the superposition of two Random Telegraph Signal noises with different time constants. The current noise power density follows the 1/f power law over a wide range of frequency (1 Hz 100 kHz). Moreover, the discrete fluctuations typical of SB are statistically independent events at least over time periods around hundreds of seconds, according to a Poisson process.