209
Compact Models for Small Geometry MOSFETs
V T V T
KT
KT
L
KT V
T
T
th
th
NOM
L
eff
bseff
NOM
( ) =
(
)+
+
+


 


 
−




1
1
2
1  

(5.104)
where:
KT 1 , KT 1L , and KT 2 are the model parameters to characterize the temperature dependence of threshold voltage for different channel lengths
and body biases
The temperature dependence of carrier mobility is given by
U T U
T
T
U T U U
T
T
U T U U
NOM
UTE
A
A
A
NOM
B
B
B
0
0
1
1
( )
( )
( )
=






=
+
−






=
+ 1 1
1
1
1
T
T
U T U U
T
T
NOM
C
C
C
NOM
−






=
+
−






( )
(5.105)
where:
UTE is the parameter to model the temperature dependence of concentration dependent mobility
U A1 , U B1 , and U C1 are the parameters to model the temperature dependence
of mobility parameters U A , U B , and U C , respectively, as discussed in
Section 5.3.1
The temperature dependence of the saturation velocity is defined by model
parameter AT as
v T v
AT
T
T
sat
s at
NOM
( ) =
−
−






1
(5.106)
The temperature dependence of S/D series resistance is modeled by a parameter PRT such that
R
T R
PRT
T
T
DSW
D SW
NOM
( ) =
−
−






1
(5.107)
The temperature coefficients are optimized to fit the measurement data
obtained at the target range of operating temperatures.