silvaco的石墨烯FET仿真
go athena
line x loc=0 spacing=1
line x loc=20 spacing=1
line y loc=0 spacing=0.005
line y loc=0.1 spacing=0.0125
init two.d alum
deposit oxide thickness=0.025 div=2
deposit material=3C-SiC thickness=0.01 div=2
deposit alum thickness=0.02 div=5
etch alum start x=4 y=-0.055
etch continue x=4 y=-0.035
etch continue x=16 y=-0.035
etch done x=16 y=-0.055
electrode x=1 name=source
electrode x=17 name=drain
structure flip.y
deposit alum thickness=0.1 div=5
electrode x=10 name=gate
structure flip.y
structure outfile=graphene_FET.str
go atlas
init infile=graphene_FET.str
material material=3C-SiC \
permitti=3.3 \
eg300=0 \
NC300=3e18 \
NV300=3e18 \
MUN=1e3 \
MUP=1e3 \
affinity=4.248 \
VSATURATION=3e7
structure outfile=graphene_silicon.str
tonyplot graphene_FET.str
solve init
solve vdrain=0.001
log outfile=graphene_FET.log
solve vgate=-1 vstep=0.2 vfinal=3 name=gate
tonyplot graphene_FET.log
quit
为探究狄拉克点不在0点的原因，使用models print 命令打印能带信息，这里参数稍有不同，是后来把MUN修改的缘故。
CONSTANTS:
Boltzmann's constant = 1.38066e-023 J/K
Elementary charge = 1.60219e-019 C
Permitivity in vacuum = 8.85419e-014 F/cm
Temperature = 300 K
Thermal voltage = 0.025852 V
REGIONAL MATERIAL PARAMETERS:
Region : 1 2 3 4 5
Material : Aluminum SiO2 SiC-3C Aluminum Aluminum
Type : metal insulator semicond. metal metal
Average Composition Fraction
X-composition: 0 0 0 0 0
Y-composition: 0 0 0 0 0
Band Parameters
Epsilon : 3.9 3.3
Eg (eV) : 0
Chi (eV) : 4.25
Nc (per cc) : 3e+018
Nv (per cc) : 3e+018
ni (per cc) : 3e+018
Bandgap narrowing parameters
bgn.e (eV) : 0.009
bgn.n (/cc) : 1e+017
bgn.c : 0.5
ubgn.b : 3.1e+012
ubgn.c : 3.9e-005
bgn.shnk.me : 0.321
bgn.shnk.mh : 0.346
bgn.shnk.eps : 11.7
bgn.shnk.ge : 12
bgn.shnk.gh : 4
Effective Richardson Constants
An** : 29.2
Ap** : 29.2
Incomplete Ionization Parameters
Gc : 2
Gv : 4
Ed (eV) : 0.044
Ea (eV) : 0.045
Recombination Parameters
taun0 : 1e-007
taup0 : 1e-007
etrap : 0
nsrhn : -1e+003
nsrhp : -1e+003
ksrhtn : 0.0025
ksrhtp : 0.0025
ksrhcn : 3e-013
ksrhcp : 1.18e-012
ksrhgn : 1.77
ksrhgp : 0.57
nsrhn : -1e+003
nsrhp : -1e+003
augn : 0
augp : 0
augkn : 0
augkp : 0
kaugcn : 1.83e-031 #Klaassen’s Temperature-Dependent Auger Model
kaugcp : 2.78e-031
kaugdn : 1.18
kaugdp : 0.72
aug.cnl : 2.2e-031
aug.cpl : 9.2e-032
aug.chi : 1.66e-030
hns.ae : 6.7e-032
hns.ah : 7.2e-032
hns.be : 2.45e-031
hns.bh : 4.5e-033
hns.ce : -2.2e-032
hns.ch : 2.63e-032
hns.he : 3.47
hns.hh : 8.26
hns.n0e : 1e+018
hns.p0e : 1e+018
copt : 0
Band-to-band tunneling Parameters
mass.tunnel : 0.25
me.tunnel : 0.243
mh.tunnel : 0.243
Thermal Velocities
vn (cm/s) : 2.37e+007
vp (cm/s) : 2.37e+007
Saturation Velocities
vsatn (cm/s) : 3e+007
vsatp (cm/s) : 3e+007
REGIONAL MODEL FLAGS:
Region: 1 2 3 4 5
SRH F
consrh F
klasrh F
Auger F
klaaug F
picaug F
hnsaug F
auggen F
optr F
bgn(std/kla) F
ubgn F
bgn.alamo F
bgn.bennett F
bgn.schenk F
incomplete F
bbt F
bbtauto F
bbthurkx F
bbtkane F
bbtschenk F
bbtnonlocal F
tat(local) F
tatnonlocal F
tat(coulombic) F
impact F
Boltzmann T
Fermi-Dirac F
Gain and Rsp scaling
Gain scale factor : 1 1
Rsp scale factor : 1 1
REGIONAL MOBILITY MODEL SUMMARY:
Region #3:
Model for Electrons:
Concentration Independent Mobility
@ Temperature = 300 Kelvin
mu = 3000
tmu = 1.5
Model for Holes:
Concentration Independent Mobility
@ Temperature = 300 Kelvin
mu = 1000
tmu = 1.5
Contacts:
Name Num Work fn Resist. Capacit. Induct.
(eV) (Ohms) (Farads) (Henries)
source 1 0.000 0.000E+00 0.000E+00 0.000E+00
drain 2 0.000 0.000E+00 0.000E+00 0.000E+00
gate 3 0.000 0.000E+00 0.000E+00 0.000E+00
上面的BGN参数代表能带变窄参数
电子亲和势也受能带变窄参数的影响
在ATLAS的用户手册，对于能带对齐有详细的解释。在MATERIAL语句中可以使用ALIGN命令导带边突变为两种材料的带隙差的ALIGN倍。就像下面展示的一样
这里的 E g 1 E_{g1} Eg1是仿真模型中带隙最小的材料的带隙，具体的情况参考ATLAS用户手册5.3节。 如果不指定ALIGN，那么ATLAS会用默认的亲和势规则进行能带突变处理：
下面是一个能带突变的例子
通过修改亲和势，可以改变狄拉克点的位置
affinity = 6
改变后的曲线
