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

Physical Models
two such models available in the program, both were developed by Intel (intelmob and
intelmob.par in model card). We then consider the Lombardi model (lombardi) which shares
the same feature as Intel’s ones in that both transverse and longitudinal field effects are considered
simultaneously in the code. In all these three models, the transverse field can be computed either based
on the structure or by definition. We will elaborate this at the end of this section.
3.1.2.1 Intel’s Local Field Models
There are two mobility models developed by Intel for all doping, lattice temperature, and field
(including both transverse and longitudinal) dependence with one single logical flag. They are
described in this section. Both models follow the same formulation of Eq. (3.2), and µ 0 ( N,
T L ) has
the same expression as Eq. (3.4), the analytical model.
For model invoked by parameter intelmob in model card,
r perp = ( 1 + E ⊥ ⁄ E crit ) – β
(3.15)
where E crit is a parameter with value of 4.2×10 4 V/cm for electrons and 3×10 4 V/cm for holes in
silicon, and β = 0.5 . These parameters are all accessible to users through mobility card.
The second model specified by intelmob.par has different expression for (Eq. (3.8))
and more user-accessible parameters for the reduction due to the transverse field:
µ srf
1
r perp = ---------------------------------------
1 + ( E ⊥ ⁄ E univ ) α
where the parameters α and E univ
are listed in Table 3.6.
(3.16)
Table 3.6
electrons
holes
α
E univ ( V/cm)
1.02 5.71×10
0.95 2.57×10
5
5
Both Intel’s mobility models use µ 0 ( N, T L , E ⊥ ) = r perp ( E ⊥ )µ 0
( N,
T L ) for the low-field mobility.
PISCES-2ET – 2D Device Simulation for Si and Heterostructures 19