Time-dependent positive charge generation in very thin silicon oxide dielectrics

1077-3118

AIP Digital Archive

Physics

We have studied the rate at which positive charge is generated starting near the oxide-silicon interface when electrons are injected from the gate through the very thin oxide layer in metal-oxide-(p)silicon tunnel diodes. By varying the oxide thickness, we find that the charging rate is not strongly controlled by the flux of tunneling electrons over a five order of magnitude range in current density. This implies that if the tunneling electrons do participate, then the charge generation in these oxides is at least a two-step process. A comparison of charge generation in aluminum and polycrystalline silicon gate devices suggests that the process does not involve aluminum-related defects. Measurements of the charging rate versus temperature, T, show that it is weakly dependent on T below 150–200 K and apparently thermally activated above this temperature range.

Electronic Resource