Impact ionization model for dielectric instability and breakdown

Abstract

A mechanism describing the incipient stages of intrinsic dielectric breakdown is formulated for the case of a wide-band-gap insulator with a low hole mobility. Dielectric instability results from the tunnel injection of electrons from the cathode contact and the subsequent impact ionization and field distortion which lead to dielectric breakdown. The model, evaluated for the parameters of SiO2, predicts an intrinsic breakdown voltage which approaches a lower limit of V=9+φ for very thin films, where φ is the cathode contact barrier in volts. As a result, both the electric field at breakdown and the critical current density increase rapidly as the film thickness is reduced below 200 Å.

Stress-induced leakage current (SILC) and oxide breakdown: are they from the same oxide traps?

“…The physics of gate-oxide wearout and breakdown has been a subject of intense study for decades. The current status of theoretical understanding is that thin oxide of 100 and below follows a wearout model [1], [4]- [8] rather than the feedback runaway model [9]- [12] that dominates thicker oxides.…”

A model to predict the degradation of silicon dioxide films in mos structures

“…3 and 4 indicated rbat positive charge trapping rate increases with increasing hotelectron energy. Gate oxide degradation is related to the trapped positive charge concentration [ 1,7] and therefore, Fig.3 indicates that thicker samples are more prone to dielectric breakdown compared to rhinner samples. …”

“…Experimental data (4 are @erArnold er al. (Rd2).Dielectric breakdown is triggered when the stress-induced trap creation reaches a critical value [Z] and in reality it occurs at Qhj = 1-10 Clem'[2,7] which is far away from our present studies. The essence of the present analysis is that without going into failure analysis of a large number of samples, the oxide thickness dependent intrinsic breakdown field EM can be estimated fiom the bulk positive charge trapping characteristics at a Qhj as low as -0.01 C/cm2.…”

Contact and Surface Effects in the Electric Field Initiation of Explosives

“…The first, due to O'Dwyer (19), assumes that the impact ionizacion leads to avalanche multiplication with eventual breakdown at the exit electrode, where most of the energy of impact-generated carriers is dissipated. The second mechanism, due to DiStefano and Shatzkes (20), suggests that impact ionization generates a space charge in the volume of the sample which concentrates the internal field at the emitting electrode; this in turn produces an increase in the emission current, with eventual catastrophic power dissipation at the entrance electrode. The choice between the two mechanisms (for a given explosive azide) can thus be made on the basis of experiments that determine whether initiation occurs near tne entrance or exit electrode.…”