Visualization of electrons and holes localized in the thin gate film of metal-oxide-nitride-oxide-semiconductor type Flash memory by scanning nonlinear dielectric microscopy

By applying scanning nonlinear dielectric microscopy (SNDM), we identified the position of electrons/holes existing in the gate SiO 2 –Si 3 N 4 –SiO 2 (ONO) film of the metal-oxide-nitride-oxide-semiconductor (MONOS) type Flash memory. The electrons were detected in the Si 3 N 4 part of the ONO film. The holes, on the other hand, were found in the Si 3 N 4 film as well as in the bottom SiO 2 film.