eldo_user

Monte Carlo Analysis
Problems in Statistical Modeling
.SUBCKT P D G S B PARAM: W=1U L=1U
M1 D G S B MODP W=W L=L
.PARAM TOX=19E-09 A_MM_TOX=0.365543U B_MM_TOX=0.001435
+ DEV_MM_TOX =’A_MM_TOX/SQRT(W*L)+B_MM_TOX’
.PARAM VTH0=-.3732829 A_MM_VTH0=0.30654U B_MM_VTH0=0.1452
+ DEV_MM_VTH0 =’A_MM_VTH0/SQRT(W*L)+B_MM_VTH0’
.PARAM U0=138.7609 A_MM_U0=0.565745U B_MM_U0=0.366454
+ DEV_MM_U0 =’A_MM_U0/SQRT(W*L)+B_MM_U0’
.MODEL MODP PMOS
+LEVEL=53
+TOX = TOX LOT/GAUSS=2% DEV/GAUSS={DEV_MM_TOX}%
+VTH0 = VTH0
DEV/GAUSS={DEV_MM_VTH0}%
+U0 = U0 DEV/GAUSS={DEV_MM_U0}%
+KF=1E-27 AF=2
+TNOM=27.0
...
.ENDS
A global variation is added on the oxide thickness and we will have nine random variables for
the LOT component of the TOX parameter: M(XM1.MODN,TOX), M(XM2.MODN,TOX),
M(XM7.MODN,TOX), M(XM8.MODN,TOX), M(XM9.MODN,TOX),
M(XM10.MODN,TOX), M(XM13.MODN,TOX), M(XM15.MODN,TOX),
M(XM17.MODN,TOX). We obtained nine independent random variables instead of only one
random for the global variations of the TOX parameter. It is very unlikely that this list of
parameters is what you want to model in this case.
The global variations can be obtained by rewriting the netlist as follows:
Eldo® User's Manual, 15.3 547