Summary: Analytic formulae for the impact ionization rate for use in compact
models of ultra-short semiconductor devices
H. C. Morrisa, M. M De Passb and Henok Abebec
a. Department of Mathematics, San Jose State University, San Jose, California CA 95192.
b. Department of Mathematics, Claremont Graduate University, Claremont, CA 91711
c. MOSIS Service, USC Information Sciences Institute, Marina del Rey, CA 90292
This paper presents a new approximate compact for-
mulae for the impact ionization (I.I.) generation rate
(GII) in ultra-short-channel devices.
For ultra short length devices it is vital to accurately
account for hot electron effects such as impact ioniza-
tion. By means of a Fermi Golden Rule calculation
with a screened Coulomb interaction, Quade, Sch¨oll and
Rudan  have shown that, in the limit of large screen-
ing length, the impact ionization rate per unit time can
be expressed in the form