Temperature dependence of the leakage current in oxide-nitride-oxide interpoly dielectrics

Atomic transport across the interfaces during the formation of ultrathin silicon oxide/nitride/oxide films

“…According to them: ͑i͒ the bottom oxide maintains the good quality of the Si/SiO 2 interface, ͑ii͒ the nitride layer increases the dielectric constant of the film, and is a diffusion barrier to boron and other doping elements, and ͑iii͒ the top oxide seals weak spots in the Si 3 N 4 and is necessary when the gate dielectric is used under symmetric electrical conditions. These and other authors [8][9][10][11] neglected the improvements that can be obtained due to the ''interaction'' of the three layers composing the ONO structure. In fact, the strictly stacked nature of the ONO structures prepared as described above is questionable in the case of ultrathin films: even extremely thin top oxide layers of approximately 1 nm prevent electron and hole currents very effectively, something that cannot be explained by a simple model of a 1 nm top oxide with a sharp boundary with the nitride layer.…”