Impact ionization and hot-electron injection derived consistently from Boltzmann transport

• Published in: VLSI design (Yverdon, Switzerland) Vol. 8; no. 1-4; pp. 455 - 461
• Main Authors: Hasler, Paul, Andreou, Andreas G, Diorio, Chris, Minch, Bradley A, Mead, Carver A
• Format: Journal Article
• Language: English
• Published: 01.01.1998
• ISSN: 1065-514X
• DOI: 10.1155/1998/73698

We develop a quantitative model of the impact-ionization and hot-electron-injection processes in MOS devices from first principles. We begin by modeling hot-electron transport in the drain-to-channel depletion region using the spatially varying Boltzmann transport equation, and we analytically find a self consistent distribution function in a two step process. From the electron distribution function, we calculate the probabilities of impact ionization and hot-electron injection as functions of channel current, drain voltage, and floating-gate voltage. We compare our analytical model results to measurements in long-channel devices. The model simultaneously fits both the hot-electron-injection and impact-ionization data. These analytical results yield an energy-dependent impact-ionization collision rate that is consistent with numerically calculated collision rates reported in the literature.