Title :
A thermal activation view of low voltage impact ionization in MOSFETs
Author :
Su, Pin ; Goto, Ken-Ichi ; Sugii, Toshihiro ; Hu, Chenming
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
Abstract :
The authors present a thermal activation perspective for direct assessment of the low voltage impact ionization in deep-submicrometer MOSFETs. A comparison of the experimentally determined activation energy and a simple theoretical model is used to demonstrate the underlying mechanism responsible for impact ionization at low drain bias. The study indicates that the main driving force of impact ionization changes from the electric field to the lattice temperature with power-supply scaling below 1.2 V. This transition of driving force results in a linear relationship between log(I/sub SUB//I/sub D/) and V/sub D/ at sub-bandgap drain bias, as predicted by the proposed thermally-assisted impact ionization model.
Keywords :
MOSFET; hot carriers; impact ionisation; semiconductor device models; 1.2 V; deep-submicron MOSFETs; electric field; lattice temperature; low drain bias; low voltage impact ionization; power-supply scaling; theoretical model; thermal activation; Current measurement; Hot carrier effects; Impact ionization; Lattices; Low voltage; MOSFETs; Photonic band gap; Predictive models; Temperature measurement; Thermal force;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2002.802653