Evaluation of fixed charge distribution and its density in the insulation layer of metal-nitride-oxide-Si structure using slanted etching method

Abstract

A fixed charge distribution in the insulation layer of metal–nitride–oxide–Si (MNOS) structure has been investigated. The distribution is determined by the mid-gap voltage of structures with various insulator thicknesses. These structures are fabricated on the same substrate by varying the etching time for the insulator gradually (slanted etching method). It was found that the fixed charges in MNOS structure before charge injection are located at the Si–oxide and the oxide–nitride interfaces. The insulator thickness dependence of the interface charge densities has also been evaluated. The charge density at the oxide–nitride interface depends on the oxide thickness. © 1999 Scripta Technica, Electron Comm Jpn Pt 2, 82(10): 10–17, 1999.