Microscopic characterization of hot-electron spreading and trapping in SiO2 films using ballistic electron emission microscopy

Ballistic electron emission microscopy was used to study three-dimensional spreading and trapping of charge in buried, 10 nm thick SiO2 films following hot-electron injection at one location. The trapped charge was found to be distributed approximately uniformly across the thickness of the oxide, and spread laterally similar to 50 nm, much more than the oxide film thickness. This large spreading can be explained by a combination of strong hot electron scattering and strong suppression in trapping efficiency at higher injected electron dose. (C) 1998 American Institute of Physics. [S0003-6951(98)03639-0].