The energy-driven paradigm of NMOSFET hot-carrier effects

As negative-MOSFET (NMOSFET) size and voltage are scaled down, the electron-energy distribution becomes increasingly dependent only on the applied bias, because of quasi-ballistic transport over the high-field region. A new paradigm, or underlying concept, of NMOSFET hot-carrier behavior is proposed here, in which the fundamental "driving force" is available energy, rather than peak lateral electric field, as it is in the lucky electron model (LEM). The new prediction of the energy-driven paradigm is that the bias dependence of the impact-ionization (II) rate and hot-carrier lifetime is, to the first order, given by the energy dependences of the II scattering rate S II(E) and an effective interface state generation (ISG) cross section S IT(E), whereas, under the LEM, these bias dependences are determined by the number of electrons with energy above the II and ISG "threshold energies." This approach allows an experimental determination of S IT. © 2005 IEEE.