Hi colbhaidh,i did the simulation set up as before adding the source capacitor and put a capacitor=1E-12 at contact=3 (my source terminal),i used here a full newton method only as you described in your earlier replies..But it is giving me a constant voltage of nearly 2.4 0r 2.5 volts always even though i am changing the voltage at source terminal..but if am using a solution file with both gummel & Newton &with no source cap value,my drain voltage is following the source voltage..Hope u understand what i want to explain you..
the mosfetgrid which i am using is:-
$*******Rectangular Grid ***************
mesh rectangular nx=108 ny=28 diag.fli outf=mosfet.mesh
X.mesh n=1 l=0 r=1
x.m n=108 l=0.99 r=1
Y.mesh n=1 l=-0.004 r=1
y.m n=6 l=0 r=1
y.m n=15 l=0.014 r=1
y.m n=28 l=0.24 r=1.30
$*********Eliminating coloumns*************
elim x.dir iy.l=9 iy.h=19 ix.l=1 ix.h=9
elim x.dir iy.l=9 iy.h=19 ix.l=28 ix.h=108
elim x.dir iy.l=8 iy.h=19 ix.l=1 ix.h=9
elim x.dir iy.l=8 iy.h=19 ix.l=28 ix.h=108
$ *************** regions ****************
region num=1 ix.l=1 ix.h=108 iy.l=1 iy.h=5 oxide
region num=2 ix.l=1 ix.h=108 iy.l=5 iy.h=28 silicon
$ ************** electrodes **************
$ 1 = Gate 2 = body 3 = source 4=bottom of holding capacitor
elec num=1 ix.l=9 ix.h=27 iy.l=1 iy.h=1
elec num=2 ix.l=1 ix.h=108 iy.l=28 iy.h=28
elec num=3 ix.l=1 ix.h=8 iy.l=6 iy.h=6
elec num=4 ix.l=30 ix.h=108 iy.l=4 iy.h=4
$ *************** doping ******************
DOP UNIF CONC=4E17 P.TYPE
DOP GAUSS CONC=5E19 N.TYPE
+ X.RIGHT=.07 y.top=0 y.bot=0.024 char=0.018
DOP GAUSS CONC=5E19 N.TYPE
+ X.LEFT=.27 y.top=0 y.bot=0.024 char=0.018
$**************** Model Card****************
MODELS Srh FLdmob CONSrh BGn CONmob
$ ************** regrid ********************
$
$ *** first regrid on potential
$
contact num=1 n.poly
symb carriers=0
solve init
regrid poten ratio=0.2 reg=2 smooth.k=1 outf=mosfetgrid45_1
end
AND the solution file which i am using (having both gummel & Newton method) is :-
title Charge Injection Test
$
mesh infile=mosfetgrid45_1
contac num=1 n.poly
contac num=2 neutral
contac num=3 neutral
contac num=4 neutral
symb gummel carriers=1 electrons
method iccg damped
solve init currents
symb newton carriers=1 electrons
method autonr
log outf=tf50nsec.log
solve v1=0 v4=0 v2=0 v3=2 outf=ab
solve v1=1.8 TSTEP=1E-9 TSTOP=10E-9 RAMPTIME=1E-9 currents
solve v1=0 TSTEP=1E-9 TSTOP=60E-9 RAMPTIME=50E-9 currents outf=t0
end
This solution file is giving me the exact results..Like when i am giving source voltage=1v my drain voltage becomes 1v,When i am giving source=2v my drain is becoming 2volts..
But when i put cap=1E-12 in the solution file(containing only newton method) i am not getting the expected values of result..The solution file which i am using is:-
title Charge Injection test
$
mesh infile=mosfetgrid45_1
contac num=1 n.poly
contac num=2 neutral
contac num=3 Alum cap=1E-12
contac num=4 Neutral
symb newton carriers=1 electrons
method ITLIMIT=200 autonr
solve init currents
log outf=tf50n_1.log
solve v1=0 v2=0 v3=1 v4=0 outf=ab
solve v1=3 TSTEP=1E-9 TSTOP=10E-9 RAMPTIME=1E-9 currents
solve v1=0 TSTEP=1E-9 TSTOP=60E-9 RAMPTIME=50E-9 currents outf=r0
end
In this file,For v1=0 v2=0 v3=0 v4=0 (i.e for solve init) it is not converging,Also for v1=0 v2=0 v3=1 v4=0 it is not converging..Remaining for all the transient values it is converging..Pleeeeeeez help me regarding this capacitor issue???? Its very important for my thesis defination...