Problem with Schottky barrier simulation in Silvaco Atlas

[dunestar]

Dear Folks,

may be you are able to give me some hints and tipps for my problem. I am trying to simulate the Id-Vg curve of a Schottky barrier Double Gate MOSFET device, but during the simulation I have converging problems, as well as the following messge in the command window. May be someone already had this problem? Tipps and tricks are welcome.

Here is my code:
go atlas

mesh space.mult=1 width=1
#
x.mesh loc=-0.0225 spac=0.00001
x.mesh loc=0 spac=0.001
x.mesh loc=0.0225 spac=0.00001
#
y.mesh loc=-0.002 spac=0.0005
y.mesh loc=0 spac=0.00025
y.mesh loc=0.010 spac=0.0005
y.mesh loc=0.020 spac=0.00025
y.mesh loc=0.022 spac=0.0005

#.... regions
region num=1 silicon x.min=-0.0225 x.max=0.0225 y.min=0 y.max=0.020
region num=2 y.min=0.020 x.min=-0.05 x.max=0.05 user.material=myoxide
region num=3 y.max=0 x.min=-0.05 x.max=0.05 user.material=myoxide

#.... electrodes
electr name=gate top x.min=-0.0225 x.max=0.0225
electr name=gate bottom x.min=-0.0225 x.max=0.0225
electr name=source x.max=-0.0225 y.min=0 y.max=0.020
electr name=drain x.min=0.0225 y.min=0.0 y.max=0.020

#.... p-type doping
doping p.type conc=1.e15 uniform region=1

#.... permittivity for myoxide
material material=myoxide user.group=insulator user.default=oxide permittivity=7

#.... save and load the structure
save outf=structure.str
#tonyplot structure.str -set structure.set

#.... use the UST model for Schottky barrier current simulation
model ust srh Print

#.... contacts with workfunction and barrier height and parameters
contact name=gate workfunction=4.47
contact name=drain SURF.REC E.TUNNEL H.TUNNEL ME.TUNNEL=0.26 MH.TUNNEL=0.36 workfunction=4.35
contact name=source SURF.REC E.TUNNEL H.TUNNEL ME.TUNNEL=0.26 MH.TUNNEL=0.36 workfunction=4.35

#.... Method of solving
method newton trap

solve init

log outf=structure.log

solve vdrain=0.05 name=drain outf=solve_vdrain05
load infile=solve_vdrain05
log outfile=mos_gate_sweep
solve vgate=-0.5 vstep=0.2 vfinal=1 name=gate

tonyplot structure.log -set structure_log.set
save outf=biased.str

quit

And here are the messages:

...
ATLAS> save outf=structure.str

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 4 contacts both sides of a junction

Warning: In line # 24
Electrode # 3 contacts both sides of a junction

...

 

[rajdeep.jzs]

I will suggest you to write the structure in devedit...you can see the structure and also you can refine the mesh in the central channel region, you won't need regrid command then...

 

[dunestar]

Hello,

thank you for the answer, I have tried it in that way, but still converging problems occur. What should I else do?