BSIM3v3.2.2 MOSFET Model - The University of Texas at Dallas
BSIM3v3.2.2 MOSFET Model - The University of Texas at Dallas
BSIM3v3.2.2 MOSFET Model - The University of Texas at Dallas
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Subthreshold Drain CurrentV1 PSCBE2 PSCBE1ASCBEl= exp( − )L V − Vdsds<strong>at</strong>(2.6.17)<strong>The</strong> variables P scbe1 and P scbe2 are determined experimentally.2.7 Subthreshold Drain Current<strong>The</strong> drain current equ<strong>at</strong>ion in the subthreshold region can be expressed as [2, 3]IdsV V V Vdsgs−th−<strong>of</strong>f= Is0 ( 1−exp( − )) exp( )vnv tttm(2.7.1)I= µs0 0WLqεsiNchv2φs2t(2.7.2)Here the parameter v t is the thermal voltage and is given by K B T/q. V <strong>of</strong>f is the<strong>of</strong>fset voltage, as discussed in Jeng's dissert<strong>at</strong>ion [18]. V <strong>of</strong>f is an importantparameter which determines the drain current <strong>at</strong> V gs = 0. In Eq. (2.7.1), theparameter n is the subthreshold swing parameter. Experimental d<strong>at</strong>a shows th<strong>at</strong> thesubthreshold swing is a function <strong>of</strong> channel length and the interface st<strong>at</strong>e density.<strong>The</strong>se two mechanisms are modeled by the following(2.7.3)C C V C V D L effDL eff( dsc + dscd ds + dscb bseff )⎛⎜exp( − VT + −⎞1 ) 2exp( VT1) ⎟Cd⎝ 2ltlt⎠ Cn= 1+ Nfactor++CoxCoxCitoxwhere the term2-30 <strong>BSIM3v3.2.2</strong> Manual Copyright © 1999 UC Berkeley
Change language