Silvaco TCAD的交流小信号仿真问题

jiamo

我打算仿真一个FinFET,提取它的直流特性和电容参数。直流仿真没问题，但是交流小信号仿真一直不收敛出不来。不知道哪里出了问题。这是我的直流仿真曲线，交流仿真曲线和代码。有没有懂的大佬帮忙看看。总是有句警告：Warning: Possible log file error for log file 3D-N-FinFET.log.
go atlas

mesh three.d

x.mesh loc=0.000 spac=0.010
x.mesh loc=0.064 spac=0.010
x.mesh loc=0.096 spac=0.010
x.mesh loc=0.128 spac=0.010
x.mesh loc=0.160 spac=0.010
x.mesh loc=0.224 spac=0.010

y.mesh loc=0.000 spac=0.010
y.mesh loc=0.002 spac=0.010
y.mesh loc=0.007 spac=0.010
y.mesh loc=0.009 spac=0.010
y.mesh loc=0.023 spac=0.010
y.mesh loc=0.025 spac=0.010
y.mesh loc=0.030 spac=0.010
y.mesh loc=0.032 spac=0.010

z.mesh loc=0.000 spac=0.010
z.mesh loc=0.090 spac=0.010
z.mesh loc=0.150 spac=0.010
z.mesh loc=0.190 spac=0.010
z.mesh loc=0.195 spac=0.010
z.mesh loc=0.197 spac=0.010
z.mesh loc=0.200 spac=0.010
z.mesh loc=0.205 spac=0.010
z.mesh loc=0.207 spac=0.010
#chengdi
region num=1 x.min=0.000 x.max=0.224 y.min=0.000 y.max=0.032 z.min=0.000 z.max=0.090 material=silicon
#yanghuawu
region num=2 x.min=0.000 x.max=0.224 y.min=0.000 y.max=0.032 z.min=0.090 z.max=0.150 material=sio2
#source
region num=3 x.min=0.000 x.max=0.064 y.min=0.000 y.max=0.032 z.min=0.150 z.max=0.195 material=silicon
#fin
region num=4 x.min=0.064 x.max=0.096 y.min=0.009 y.max=0.023 z.min=0.150 z.max=0.195 material=silicon
region num=5 x.min=0.096 x.max=0.128 y.min=0.009 y.max=0.023 z.min=0.150 z.max=0.195 material=silicon
region num=6 x.min=0.128 x.max=0.160 y.min=0.009 y.max=0.023 z.min=0.150 z.max=0.195 material=silicon
#drain
region num=7 x.min=0.160 x.max=0.224 y.min=0.000 y.max=0.032 z.min=0.150 z.max=0.195 material=silicon
#gate
region num=8 x.min=0.096 x.max=0.128 y.min=0.000 y.max=0.007 z.min=0.150 z.max=0.207 material=polysilicon
region num=9 x.min=0.096 x.max=0.128 y.min=0.007 y.max=0.009 z.min=0.150 z.max=0.197 material=hfo2
region num=10 x.min=0.096 x.max=0.128 y.min=0.007 y.max=0.025 z.min=0.197 z.max=0.207 material=polysilicon
region num=11 x.min=0.096 x.max=0.128 y.min=0.009 y.max=0.023 z.min=0.195 z.max=0.197 material=hfo2
region num=12 x.min=0.096 x.max=0.128 y.min=0.025 y.max=0.032 z.min=0.150 z.max=0.207 material=polysilicon
region num=13 x.min=0.096 x.max=0.128 y.min=0.023 y.max=0.025 z.min=0.150 z.max=0.197 material=hfo2
#electrode
electrode x.min=0.000 x.max=0.064 y.min=0.000 y.max=0.032 z.min=0.190 z.max=0.195 name=source
electrode x.min=0.160 x.max=0.224 y.min=0.000 y.max=0.032 z.min=0.190 z.max=0.195 name=drain
electrode x.min=0.096 x.max=0.128 y.min=0.000 y.max=0.002 z.min=0.150 z.max=0.207 name=gate
electrode x.min=0.096 x.max=0.128 y.min=0.002 y.max=0.030 z.min=0.205 z.max=0.207 name=gate
electrode x.min=0.096 x.max=0.128 y.min=0.030 y.max=0.032 z.min=0.150 z.max=0.207 name=gate
#dope
doping region=3 n.type concentration=1.0e21 uniform
doping region=7 n.type concentration=1.0e21 uniform
doping region=5 p.type concentration=1.0e16 uniform
contact name=gate workfunction=4.8

models srh fermidirac CVT  
method   gummel NewTON maxtrap=20

output  e.field  e.velocity  e.temp  h.velocity  h.temp  band.param  band.temp  con.band  val.band e.mobility
log outfile=3D-N-FinFET.log
solve init
solve vdrain=0.1
solve vgate=-0.1 vstep=0.05 vfinal=0.8 name=gate
save outfile=N-FinFET.str
tonyplot3d N-FinFET.str
log off
tonyplot   3D-N-FinFET.log
#
extract name="vt" (xintercept(maxslope(curve(abs(v."gate"),abs(i."drain")))) - abs(ave(v."drain"))/2.0)

#
extract name="subvt" 1.0/slope(maxslope(curve(abs(v."gate"),log10(abs(i."drain")))))
quit