Generation of interface states at the silicon/oxide interface due to hot-electron injection

Abstract

By considering the decomposition of water-related bonds at the silicon/oxide interfaces, theoretical expressions for the hot-electron induced interface state generation and threshold-voltage shift are developed. Results demonstrate that the relation between the threshold-voltage shift and the hot-electron fluence needs not follow the power law. The developed expression of the threshold-voltage shift is a function of the initial interface trap density, interface hardness, density of water-related chemical bond, and the capture cross section of interface trap and can be used to explain most of the reported experiments. When the trapping rate and the generation rate are close to each other, a power law dependence of the threshold-voltage shift will be observed in a wide range of injection fluence. However, if the trapping rate is greater than the generation rate or for a sample with large hardness and small initial trap density, a quasi-saturation region is observed because of most of the interface trap being filled and the small amount of generated traps. Saturation of the threshold-voltage shift will occur when most of the water-related bonds are dissociated and the created traps are filled.