Generation-annealing kinetics of the interface donor states at 0.25 eV above the midgap and the turn-around phenomena on oxidized silicon during avalanche electron injection

Abstract

The generation and the annealing kinetics of the donorlike peaked interface density of states (DOS’s) at 0.25 eV about the midgap and the turn-around phenomenon of the flat-band voltage generated by the avalanche electron injection are reported. The generation of the peaked interface DOS follows a first-order kinetics and it anneals out at 25 C following a second-order kinetics. The devices with dry oxide show a small buildup of peaked DOS as well as a small turn-around phenomenon. However, after a deionized (DI) water rinse before gate metallization, a large buildup of peaked DOS and turn-around states were observed. After avalanche electron injection is terminated, in the devices with small peaked DOS, the midgap slowly drifts in the negative voltage direction under negative gate bias. However, in the devices with large peaked DOS, the midgap voltage slowly drifts in the positive gate voltage direction even under negative gate bias. Detailed analyses of both the generation and annealing data suggest that the peaked DOS is a donor which can account for most of the turn-around phenomenon as well as the midgap voltage instabilty phenomenon after avalanche electron injection. DI water dependence suggests that the peaked DOS and the turn-around states may be related to hydroxyl species in the oxide.