On the Mechanism for Interface Trap Generation in MOS Transistors due to Channel Hot Carrier Stressing

The classical concept and theory suggest that the degradation of MOS transistors is caused by interface trap generation resulting from "hot carrier injection". We report three new experiments that use the deuterium isotope effect to probe the mechanism for the interface trap generation in n-MOS transistors in presence of hot hole and electron injection. These experiments show clearly that hot carrier injection into the gate oxide exhibits essentially no isotope effect, whereas channel hot electrons at the interface exhibit a large isotope effect. This leads to the conclusion that channel hot electrons, not carriers injected into the gate oxide, are primarily responsible for interface trap generation for standard hot carrier stressing.