Breakdown mechanism of Al2O3 based metal-to-metal antifuses

An impulse thermal breakdown model is proposed to understand the breakdown mechanism of Al2O3, thin film based metal-to-metal antifuses. In this model, the electric field dependence as well as the temperature dependence of the electrical conductivity is considered. The I-V characteristic of the antifuses indicated that the conductivity of Al2O3 rose greatly under high field. The threshold breakdown voltage of the antifuses was shown by experiment to be proportional to its insulator thickness and to the square root of the insulator resistivity. When breakdown of the antifuses was carried out by applying constant voltage pulse, the inverse square root of the time to breakdown was shown to be proportional to the amplitude of the pulse. All the experimental results were found to be consistent with the theoretical results of the model. In addition, an antifuse breakdown filament with a diameter of 150 nm was observed by using a scanning electron microscope. (C) 2000 Elsevier Science Ltd. All rights reserved.