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

Physical Models
3.1.1.4 Arora’s Doping and Temperature Dependent Mobility Model
An empirical mobility model based on the fitting to the measurement data for silicon at different lattice
temperature has originally been proposed by Arora and et al. [5] and can be invoked by using
parameter arora in the model card. The model has a general form of the following:
µ 0
µ
( N,
T L ) = µ min + -------------------------------- dlt
1 + ( N ⁄ N 0 ) α
(3.9)
† units of cm 2 V -1 s -1 b
where parameters µ min , µ dlt , N 0
, and α are all functions of T L
in the form of aT L where both a and b
are constants. This model is later extended to apply to GaAs by Yu [6] based on the available measured
data at 77 and 300 K. The parameter values for silicon and GaAs are listed in Table 3.4.
Table 3.4
†
µ min
†
µ dlt N 0 (cm -3 )
α
electrons
– 0.57
88T L
– 2.33
1252T L
17 2.4
1.25×10 T L
– 0.146
0.88T L
– 0.57
– 2.23
17 2.4
– 0.146
silicon holes 54.3T L 407T L 2.35×10 T L 0.88T L
electrons
– 0.7475
2136T L
– 2.687
6331T L
16 3.535
7.345×10 T L
– 0.1441
0.6273T L
– 1.124
– 2.366
GaAs holes 21.48T L 331.2T L
17 3.690
5.136×10 T L 0.8057
3.1.1.5 User Definable Arora’s Mobility Model
This model uses exactly the same formulation for doping and (lattice) temperature dependent mobility
as Arora’s model discussed above. The only difference is that all the coefficients are put in an
initializable subroutine initum1 in file usrmob1.f. If users want to change some of the
coefficients in the model, they have to change this file and re-compile the program. This model can be
invoked by parameter user1 in model card and is applied to silicon only.
PISCES-2ET – 2D Device Simulation for Si and Heterostructures 17