Oxide-Voltage and Its Polarity Dependence of Interface-State-Generation Efficiency in (100) n-Si Metal/Oxide/Semiconductor Capacitors

The polarity dependence of Fowler-Nordheim (F-N) tunneling current stress on the interface-state-generation efficiency in (100) n-type Si metal/oxide/semiconductor (MOS) capacitors has been investigated as a function of oxide voltage using the ac conductance method. The interface-state-generation efficiency η gen is larger when the F-N tunneling electrons are injected from the gate (gate emission) than when they are injected from the substrate (substrate emission) by about two orders of magnitude over the whole range of the oxide voltage employed. Moreover, the values of η gen for both polarities depend significantly on the oxide voltage in a similar fashion. The measured generation efficiency is combined with the critical electron fluence Q BD for dielectric breakdown reported to date to demonstrate that the critical interface-state density for breakdown is independent of Q BD and the oxide voltage.