The energy-driven paradigm of NMOSFET hot-carrier effects

Abstract

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 .

A predictive physical model for hot-carrier degradation in ultra-scaled MOSFETs

“…One can see that EES substantially changes the shape of the high-energy tail of the DFs. then used to calculate the carrier acceleration integral (AI)[4,5,[14][15][16] (seeFig. 4).…”

Study of HCI Reliability for PLDMOS

“…A process of electrons tunnel through a barrier in the presence of a high electric field was taken into account by using Fowler-Nordheim model. While, the luckyelectron model provides an estimate of the probability that some carriers in silicon will be transmitted to the oxide by overcoming the local energy barrier at the Si-SiO 2 interface [5][6][7].…”

Key Issues and Solutions for Characterizing Hot Carrier Aging of Nanometer Scale nMOSFETs

“…For example, the worst HCA used to occur under V g = V d /2 = V dd /2, but HCA of nanodevices under V g = V d = V dd is substantially higher than that under V g = V dd /2 [5], [9], [11]. It is proposed that the HCA of nanodevices is driven by carrier energy and carrier-carrier interaction [11], [14], [16], [17] and multivibration excitation [11] plays important roles. The objective of this paper is to investigate some key issues in characterizing the HCA of nano-nMOSFETs.…”