PISCES-2ET and Its Application Subsystems - Stanford Technology ...

Physical Models
3.1.3.4 Local Field Dependent Mobility Transformed from Haensch’s Model
The following mobility model preserves the local field dependency, but it is transformed from
Haensch’s formulation (Eqs. (3.33)-(3.34)). The model is valid for silicon only and can be invoked
through parameter fmob.new in model card.
2
µ ( N, T L , E ⊥ , E||
) = µ 0
( N, T L , E ⊥ )-------------------------------------------------------------------------
1 1 4 µ 0( N , T L,
E ⊥)E --------------------------------------- 2 ||
+ +
v sat
(3.35)
3.2 Thermal Conductivity Formula
The thermal conductivity, κ, in the expression of carrier-energy/heat flux plays equally important role
as mobility does in the current density expression. In CHAPTER 2 we have given expressions of κ for
carriers in terms of the mobility. For thermal conductivity of the lattice, κ L
, it is assumed that the power
dependence on the lattice temperature is observed, i.e.,
κ L ( T L )
– α
= κ 0 T L (3.36)
where κ 0
is the thermal conductivity at T L
= 300 K and varies from material to material while α is a
constant (1.2) for all materials. Table 3.10 lists κ L
for different materials as implemented in the code.
Table 3.10
material κ (W K -1 cm -1 0 ) material κ (W K -1 cm -1 0
)
silicon 1.45 oxide 0.25
GaAs 0.44 nitride 0.25
AlAs 0.91 sapphire 0.25
InAs 0.29 insulator 0.25
InP 0.80 Al 0.5 Ga 0.5 As 0.0903
PISCES-2ET – 2D Device Simulation for Si and Heterostructures 27