Electron trapping during high-field tunneling injection in metal-oxide-silicon capacitors: The effect of gate-induced strain

Abstract

It is shown that the electron trapping during Fowler–Nordheim tunneling in metal-oxide-semiconductor capacitors is a function of the gate-induced strain. The trapping probability is modulated by the strain induced by the gate electrode. A larger induced compressive strain results in a smaller probability of trapping. A silicon-rich silicon-dioxide injector stack was utilized to obtain spatially uniform injection under both positive and negative gate bias. Devices without the injector exhibited perimeter-dominated current under negative gate bias because of the field enhancement near the edges. The electron trapping dependence on the gate-induced strain is invoked to explain the sublinear dependence of the perimeter-related current. It is shown that only traps of capture cross section greater than 10−18 cm2 are affected by this strain, apparently by modulating the capture cross section.