semiconductor device modeling and characterization ee5342, lecture 23 spring 2003
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L23 08April03 1
Semiconductor Device Modeling and CharacterizationEE5342, Lecture 23Spring 2003
Professor Ronald L. Carterronc@uta.edu
http://www.uta.edu/ronc/
L23 08April03 2
Discussion of IC-CAP Parameter Extraction Lang.• Download and bring a copy of:
– http://www.uta.edu/ronc/neff.txt– http://www.uta.edu/ronc/iseff.txt– copy as *.xfm to your gamma acct– import *.xfm to appropriate setup
• A brief PEL overview in 4/8 lecture.• IC-CAP user guide at:http://eesof.tm.agilent.com/docs/iccap/ic_ug/icug_2001.pdf
L23 08April03 3
Importing an .xfm file into a DUT
• open DUT• select Extract / Optimize• /File/Open - select .xfm - select
"browse" to select neff.xfm• Be sure variables selected are in DUT• Can plot in DUT/Plots as neff, neff.m
and neff.s• Likewise for iseff
L23 08April03 4
neff.xfmLINK XFORM ”neff"{data{HYPTABLE "Link Transform"{element "Function" "Program"}BLKEDIT "Program Body"{ k = 1.38066e-23 q = 1.60218e-19 T = 273.16 + TNOM Vt = k*T//q
L23 08April03 5
neff.xfm (cont.) vbe = vb - ve ! neff = dv/d(ln(i))/(Vt) lnic = log(ic.b) y = derivative(lnic,vbe,1) !dy/dx = derivative(x,y,1) return y//Vt}dataset{datasize BOTH 51 1 1. . . meas and simu data ...}}}
L23 08April03 6
iseff.xfmLINK XFORM "iseff"{data{HYPTABLE "Link Transform"{element "Function" "Program"}BLKEDIT "Program Body"{ k = 1.38066e-23 q = 1.60218e-19 T = 273.16 + TNOM Vt = k*T//q
L23 08April03 7
iseff.xfm (cont.) vbe = vb - ve ! neff = dv/d(ln(i))/(Vt) lnic = log(ic.b) y = derivative(lnic,vbe,1) !dy/dx = derivative(x,y,1) ne = y//Vt return exp(log(ic)-vbe/(ne*Vt))}dataset{datasize BOTH 51 1 1. . . meas and simu data ...}}}
L23 08April03 8
Values for gate workfunction, m
V 17.5q/E :Si-poly p
V 05.4 :Si-poly n
V 55.4 :W ,Tungsten
V 65.5 :Pt ,Platinum
V 6.4 :Mo ,Molybdenum
V 1.5 :Au ,Gold
V 28.4 :Al ,umminAlu
gSim
Sim
m
m
m
m
m
L23 08April03 9
Values for ms
with metal gate
02586.0V ,12.1E ,19E8.2N
10E45.1n ,05.4 ,28.4
NN
lnV :Si-n to Al
nN
lnVq2
E
n
NNlnV :Note
n
NNlnV :Si-p to Al
tgC
iSiAlm,
d
CtSiAlm,ms
i
at
g2i
aCt
2i
aCtSiAlm,ms
L23 08April03 10
Values for ms
with silicon gate
i
dt
g
d
Ct
d
CtSi
gSims
i
at
g2i
aCt
2i
aCtSiSims
nN
lnVq2
E
NN
lnV :Note
NN
lnVq
E :Si-n to poly p
nN
lnVq2
E
n
NNlnV :Note
n
NNlnV :Si-p to poly n
L23 08April03 11
Experimental valuesfor msFig 10.15*
L23 08April03 12
Calculation of thethreshold cond, VT
Ox the across Q induce to added
voltage the isV where V,VV
sub)-p sub,-(n xNqQ is
charge extra the and x of value
the reached has region depletion
The inverted. is surface the when
reached is condition threshold The
d,max
FBT
d,maxBd,max
d,max
L23 08April03 13
Equations forVT calculation
substr-n for 0 substr,- p for 0V
qN
22x ,xNqQ
,0nN
lnV ,0Nn
lnV
C
Q2VV :substrn,p
d,a
n,pd,maxd,maxa,dd,max
i
dtn
a
itp
Ox
',maxd
n,pFBT
L23 08April03 14
Fully biased n-MOScapacitor
0y
L
VG
Vsub=VB
EOx,x> 0
Acceptors
Depl Reg
e- e- e- e- e- e- n+
n+
VS VD
p-substrate
Channel if VG > VT
L23 08April03 15
Effect of contacts,VS and VD
material type-n induced allyelectronic
the contacts V and type-p the
contacts V since ,VV2VV
bend-band total let size, D.R. compute To
... ,VV21
V where ,VVyV
so ,V at not are regions contact The
C
BCBpabi
DSavgC,CGOx
B
L23 08April03 16
Computing theD.R. width at O.S.I.
Ex
Emax
x
aSi
x Nq
dxdE
a
CBpSi,maxd qN
VV22x
CBp VV2area
,maxda,maxd xqNQ
L23 08April03 17
Computing thethreshold voltage
DR the charge
and channel the invert to
required is where ,
'
'2 ,max
VVV
C
QVVV
FB
Ox
dSpFBT
L23 08April03 18
)VV(2/1V or VVV
VV,V
DsGsGox
BDs
)VV(2 Bending Band Total
VVVVV
)n/Nln(V2
NnN,NN 2V
from goes BB Total
sBp
sBnsidepsidea
iat
asdaapbi
L23 08April03 19
aqN
))sVBV(p2(E2
max,dX
O.S.I. At
xE
maxE
max,dXX
max,damax.d XqNQ
)VV(2area sBp E
aqNdxdE
L23 08April03 20
oxmax,dFB...ThGBBT
BsGT
oxmax,dsPFBT
C/)Q(BB.TVVVV
chosen values V&V for VV
C/)Q(V2VV
L23 08April03 21
Fully biased MOScapacitor in inversion
0y
L
VG>VT
Vsub=VB
EOx,x> 0
Acceptors
Depl Reg
e- e- e- e- e- e- n+
n+
VS=VC VD=VC
p-substrate
Channel
L23 08April03 22
Flat band with oxidecharge (approx. scale)
Ev
Al SiO2p-Si
EF
m
Ec,Ox
Eg,ox
~8eV EFp
Ec
Ev
EFi
'Ox
'ss
msOxmsFB
Ox
Oxc
Ox
'ss
x
ssm
ss
C
QVV
xV
dxdE
q1Q
E
surface gate the on
is Q'Q' charge
a cond FB at then
bound, Ox/Si the at
is Q' charge a If
q(fp-ox)
q(Vox
)q(m-
ox)
q(VFB
) VFB= VG-VB, when Si bands
are flat
Ex
+<--Vox-->-
L23 08April03 23
Flat-band parametersfor n-channel (p-subst)
0nN
lnVq2
E
n
NNlnV
gate, Si-poly n a For
den chg Ox/Si the is 'Q ,x
'C
'C'Q
V :substratep
i
at
g2i
actms
sms
ssOx
OxOx
Ox
ssmsFB
L23 08April03 24
MOS energy bands atSi surface for n-channel
Fig 8.10**
L23 08April03 25
Fully biased n-channel VT calc
0V ,
qN
VV22x
,xNqQ' ,0Nn
lnV
VV'C
'Q2VVV
VV :substratep
a
CBpd,max
d,maxad,maxa
itp
FBOx
,maxdpFBCT
Tthreshold at ,G
L23 08April03 26
References
* Semiconductor Physics & Devices, by Donald A. Neamen, Irwin, Chicago, 1997.
**Device Electronics for Integrated Circuits, 2nd ed., by Richard S. Muller and Theodore I. Kamins, John Wiley and Sons, New York, 1986
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