Influence of high-field electron injection regimes on modification of dielectric films of MOS devices

Abstract

The influence of high-field electron injection regimes on modification of metal-oxide-semiconductor (MOS) transistors with multilayered gate dielectric SiO2-PSG containing electron traps is studied. It is shown that the preferable regime for injection modification of MOS transistors is the regime of electron injection from the silicon substrate for which the maximum shift of the threshold voltage is higher and the gate dielectric breakdown probability is much lower as compared to injection from an aluminum electrode. The amplitude of current pulses used for charge injection into the gate dielectric should be chosen from the geometric size of the transistor and particular electrophysical characteristics of the dielectric film and should be in the range 10−7–10−4A/cm2. It is shown that, for obtaining MOS devices with high thermal field stability after modification of the charge state by electron injection, it is necessary to anneal devices at temperatures of about 200°C.