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ECE 654: Plasma Processing (tentative). Week 1-3: Introduction, dc Discharges, PDP/BLU Week 4-6: Waves, Transport, CCrf Disch. Week 7-9: ICP, Collisions Week 10-12: Global Modeling, NL Sheath Week 13-15: Etching, Diagnostics. Plasma Application Modeling @ POSTECH. - PowerPoint PPT Presentation
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ECE 654: Plasma Processing(tentative)
• Week 1-3: Introduction, dc Discharges, PDP/BLU• Week 4-6: Waves, Transport, CCrf Disch. • Week 7-9: ICP, Collisions• Week 10-12: Global Modeling, NL Sheath• Week 13-15: Etching, Diagnostics
Plasma ApplicationModeling @ POSTECH
Introduction of PDP
R G B
R G B
Visible Light
방전 발생 여기종 형성 자외선 발생
광 photon 변환 광 photon 방출
Present PDPs
1.5~2 lm/W
High efficiency cell structure with low power consumption should be needed
Energy Flow in PDP cell
Future PDPs
5 lm/W
Investigation of Plasma Characteristics in a PDP Cell
(a) t = 0.40s
(b) t = 0.70s
(c) t = 1.00s
Radiation transport in PDP Striation phenomenonanode cathode
Pulse simulation
anode cathode
Xe ion Electron
Ion angle distribution on MgO
Plasma ApplicationModeling @ POSTECH
y
x
z
z
y
x
We can consider the 3-D effects of barrier rib and electrode shape.
Examples of electrode shape
3-D Fluid Code for PDP (FL3P)
Ch.14. DC Discharge§14.1 (p.451) Def of Various Regimes of a dc normal glow
PDP: neg glow only (~1lm/w)
fluores. light: pos. glow (~70lm/w)
§14.2 Positive Glow Column (s.s.) 1-D analysis ( ch.5 & same as for rf discharge. ch.10)
(1)Te
Improved eq. For Te
(2)
’60 ’80 2000 yr
Lm /w
50
40
20
Hysteresis
10e- 6 10e- 3 10e- 1
Vs
V
IA
IB
IC
Fig 14.2
Neg. Glow Cathode
Sheath
Positive
glow
Anode fall
DC
l
R
)0)((.
))(
0)()(1
01
00
2
2
Rn b.c
R
χ
Dβ
rJnrn
Drnrn
dr
d
rdr
d
nnDt
n
a
iz
a
iz
iza
(
cyl.
2.405
)(0 RJ
01χ
ssun (14.2.10) .n determin in used be to
(14.2.6)
0
)()( 10 RJDuRJ izas
Eq. for Te
lossabs PP : radial) D-(1 balancepower
for (14.2.14) ; for (14.2.15)
EnEn 00 &
s.s.
Townsend
arc
405.201
Ch.2◎Kinetic Eqs & Equil.Maxwell DistrDistribution Function as averaged quantity from truly kinetic
: A bit more continuum(averaged, coarse-grained)Defined only on phase space meshes Fluid: n(xi,t) define only on spatial meshes Boltzmann eq with an unclosed form of collision term
L&L(2.3.3),Golant(3.17)-Kinetic Simulations •Mol-Dynamics Sim •Particle Sim(P-P) •PIC (PIC/MCC;P3M;P-M) •Vlasov sim(Boltzmann Sim)
),.()(/
),()(
),1()()(
PPDMMP
j
jj
pjj
simulparticlePIC
txEm
q
dt
tdv
Njtvdt
tdx
),( tf vr,(Newtonian eqs)
)( BvEv
a
m
q
t
ct
f
v
tf
tt
tf
tt
tf
),,(),,(),( vrvvrrvr,
),,( tvxf ii
Plasma ApplicationModeling @ POSTECH
0 10 20 30 40 50 60 70 80 90107
108
109
1010
1011
Ne ions Xe ions
Ion
angl
e di
stri
buti
on
Incident ion angle ( O )
0 25 50 75 100 125 150
108
109
1010
1011
Ne ions Xe ions
Ion
ener
gy d
istr
ibut
ion
Incident ion energy (eV)
12
0 20 40 60 80 100
109
1010
1011
IED
of
Xe+
Incident ion energy
Xe+ @ Xe 5% Xe+ @ Xe 15%
0 25 50 75 100
108
109
1010
1011
Ne+ @ Xe 5% Ne+ @ Xe 15%
IED
of
Ne+
Incident ion energy (eV)
Angle and energy dist. - Xe 5%, 300 Torr
Plasma ApplicationModeling @ POSTECH
Xe 10% - Ne 90%
Xe+
Ne+
El
13VA
B
Anode region
1st bunch2nd bunch
- Point B becomes the center region of next striation hump.- Potential difference between points A and B is about 13V.
Striation issue (2)
Strong coupled ( P.E >> K.E. ) matter ( ie, solid ) Weakly coupled matter (ie, plasma, K.E.>>P.E. )
-Derivation of the Debye-shielded Potential
]/ exp[)(
and, )()(
)/e ( /e 1
1 - )/)( exp(
, : )(
0
0
20
0
20
2
2
221
0
)(20
D
Dee
ee
e
eix
eeii
xx
kT
enx
kT
en
dx
xd
kTkT
kTxeen
eqeqnqnqx
◎ T (eV) vs T(K)
)297()
600,111..
)(1086.0)(106.1
1038.1)(
1038.1)()(
419
23
23
K
KeVge
KTKTVT
KTkVeT B
4-
B-19
10860.026eV(0. 2.
1.
k , 101.6e :
◎ )(n vs(Torr)P 3NN
cm
319
313
23
3
10
102.311..
][)
)300)(1038.1(
)133(10][
cm
cmge
mTorrP
K
PamTorrP
Tk
Pn
N
N
NB
NN
N
NN
3-13
n 300Torr,For 2
n ; P 1mTorr,For
133PaTorr 1 gas, ideal :
(cm 103.2
mmHg
J = 2.65
LangmuirProbe by Godyak
Thomson Scattering by Elsabbagh, Muraoka
J = 3.8 mA/cm2
Using PIC-MCCSimulation
J = 3.8
EEDF Comparison for a Small-Gap CCP
•Fluid Eqs. & MHD Eqs.MHD eqs. vBJv 2 nmvP
dt
dnm
2-fl. Eq. )( BvE nq
Pdt
dnm
fluididealeqEuler
nmvPdt
dnm
fluidviscouseqstokesNavier
v
vv
)(.
).(
2
PdVPdForce s
dt
dnmwithbalancedbeto
Pdensityforce
v
-Fluid eqs.from Kinetic Eq.c
t
fft
ftf
t|),,(),,(
υavr
rvvr
Taking 0th moment of 0 Eq. of Continuity
0)(),(
vr ntnt
1st moment of 1 Eq. of motion
vBvErvv 2)(),()(
mnvqnPtt
nm
2nd moment of Energy balance eq.
0])2
1([
)22
1
2
3
2
1(
2
222
HEv
nm
BnkTnm
t O
o
2
nmPmkT //2
3
)( densityvolumeforce
◎Saha eq
-F.chen: (T in °K, n in m-3)
-Golant: (T in eV, n in cm-3)
-Boulos: -Boltzmann statistics
Thus
kTiε
iN
i en
T
n
n
23
21102.4
kTi
N
en
T 24
3
1110
23
43
2)2(
h
me
kTi
e eph
kTm
3
25
23
2
2 )()2(2
1
) ) ( (kT n n n pN i e
e
izyxN
e
m
p
kTdpdpdpdzdydx
h
n
nd
2
1exp
))()()((
236
dzdydxdp
e
kTi
m
p
kTdpe
h
V
2
1exp)(
2
3
DinkTme 3)2( 23
kTi
e
N
e eh
kTmVnn
3
23
)2()(
in1
kTi
N
eh
kTem
ninen
23
2
2
4mm Capillary tube, 15psi H2
4mm capillary tube, 15psi H2After Neutral density filter
4mm Capillary tube, 15psi H2
L&L ch. 14
-Lamps, plasma display, BLU-Magnetron sputter, hollow cathode,
PVD
JK LEE(Spring, 2007)
14.3 Cathode Sheath : Vac. Breakdown ; Paschen Law(14.3.9)
vbbrkdn Ar
• Townsend 1st Ionization Coeff.
z
dzzz
zdzz
d
ee
ize
e
0
')'(exp)0()(
)(
1
)(
dpx
Ax
BxV
V
dBppAd
BppA
d
asssumeduniformzconst
d
dzz
coeffemissionnd
dzzd
dd
se
b
seb
se
se
seise
eii
eeii
d
d
;
)1
1ln(ln)ln(
)1
1ln()exp(
)7.3()/exp(
)1
1ln(
!:)(;
)4.3(1')'(exp1
2:)0(
1')'(exp)0()()0(
)0()()()0(
0
0
• Breakdown or No-Breakdown (in simulation)1) Ni or Ne increasing exponentially (faster than linear in t)2) Ni > Nthr. ~ 3) The profile shapes of & Ni
31210 cm
Meaning of brkdnne
tne
p
z
ie
ne(z)
)()()0()0(
)0(
dd
balancedLSt
n
onconservatifluxthefrom
eiei
p
z)(
E(z)/pNon-unif.
)(z ?
Question:what’s needed to breakdown Ar? at Pn = 1Torr, d =1 cm
pdx
Plasma ApplicationModeling @ POSTECH
Necessity of Simulation
Using various simulation codes (fluid, kinetic and hybrid codes)
Research Objective
Suggestion of new PDP cell and pulse with high efficiency and its optimization
Study of plasma discharge characteristics
Comparison with experimental measurement
Requirement of Simulation
Limitation of experimental measurement in understanding the plasma dynamics (wall charge, potential, and excited species density distributions)
Estimation and leading of research direction
- Small system size (a few hundred m)- Short discharge time (less than 1s)
2-DModeling of PDP cell using numerical simulation codes
3-D
bus electrode
dielectricITO electrodeMgO layer
barrier phosphors
addresselectrode
Front panel
Back panel
Plasma ApplicationModeling @ POSTECH
Diagnostics of Fluid Simulation
Density distributionsDensity distributions
Frame 001 19 Apr 2005 rib_height_125um_with_reflection.vecFrame 001 19 Apr 2005 rib_height_125um_with_reflection.vec
Wall charge distributionsWall charge distributions Potential distributionsPotential distributions
anodecathode
Light distributionsLight distributions
New PDP Cell Structures using Simulation
210
01260
80 % 90 %
150 % 110 %
conventional model
conventional model conventional model
Plasma ApplicationModeling @ POSTECH
Session 1
Flat fluorescent lamp for LCD backlight
Plasma ApplicationModeling @ POSTECH
Display devices
Emissive device
Transmissive device
TFT-LCDs need back-light unit (BLU) for light source!
2002 2004 2006 2008 20101998 2000
EEFL By G.S.CHO
CC
FL
EE
FL
Home LCD TV
Flat Lamp
[Year]
Mercury-Free Lamps
Qau
nti
ty (
arb
itar
y)
Pre
sent
Lamp (LCD) Industry Forecast (GS Cho)
eee
ee
ee Thermionic electron emission (large tube, complex driving methods,
short life)
Ion-Induced electron emission (small & thin tube, simple driving, long life)
Wall electron emission ( simple manufacturing & driving, long life)
Hot Cathode F.L. : general lighting, long & large tubing Cold Cathode F.L. : LCD-BLU, Neon-Sign HID Lamp : Arc-Discharge : Outdoor, Automobile Electrode-less Lamps
Inductive Coupled Discharge : QL lamp, Endura lamp (High Power, High Fr. Discharge) Capacitive Coupled Discharge : External Electrode F.L.(Low frequency)- Possibility of a new lamp.
GS ChoGS Cho
LOGO
Y.S. Seo, S.M. Lee and J.K. Lee
Department of Electronic and Electrical Engineering,POSTECH
Plasma ApplicationModeling POSTECH
LCD Backlight (Flat Fluorescent Lamp)
2006.
Xe* density distribution evolution (I)
case4
reference
(a) t = 200.1s
(b) t = 200.25sMax. density 2.01E11 Max. density 6.68E11
Max. density 1.56E12 Max. density 6.42E12
(a)
(b)
(c)
(d)
(e)
(f)
200 202 204 206 208 2100.0
2.0x1010
4.0x1010
6.0x1010
8.0x1010
Time [us]
electron Xe+ Xe*
(c)
Plasma ApplicationModeling, POSTECH
Simulation results (I) (b) t = 200.25s
Max. density 6.43E12(e) t = 202.05s
Max. density 6.41E12
168%
214%
400 600 800 1000 1200 1400 16000
4
8
12
16
20
24
28
32
36
40
reference dome+case3 dome+case4
Lu
min
ou
s ef
fici
ency
[lm
/W]
Sustain voltage [V]
400 600 800 1000 1200 1400 16000
2000
4000
6000
8000
10000
reference dome+case3 dome+case4
Lu
min
ance
[cd
/m2 ]
Sustain voltage [V]
400 600 800 1000 1200 1400 16000.00
0.05
0.10
0.15
0.20
0.25
reference dome+case3 dome+case4
Po
wer
co
nsu
mp
tio
n [
W]
Sustain voltage [V]
Plasma ApplicationModeling, POSTECH
Simulation results (II)
10mm
2mm
1.2mm
0.5mm
1.0mm
5mm1mm 1mm1.5mm 1.5mm
0.5mm
400 600 800 1000 1200 1400 16000
5
10
15
20
25
30
35
40
reference dome+case3 dome+case4 dome+case4+diel
Lu
min
ou
s ef
fici
ency
[lm
/W]
Sustain voltage [V]
168%
214%228%
Plasma ApplicationModeling GroupPOSTECH
LAPS Equipment(1,020mm 830mm 437mm)
Stainless-steel
Antenna
Area for 2-D simulation
Subst
rate
8th generation flat panel (2.2X2.5 m); 7th (1.87X2.2 m)
Ch.4Review (Single ptl Motions)
y
BvqBqvF
qB
Bmv
z
BF
qEuBE
tkzBy
tkzEx
v
v
qB
Bvmv
Bqvmv
VV
qB
m
qB
m
B
BVEqmdt
d
Bt•
bebee.I.
magneticdiadirection
va
m
qB
tytxat
czxy
zz
mc
xtzyx
y
x
cE
pEei
pc
pE
pepi
polariz
E
c
ccc
ccc
q
2
32
21
2
)0(
)1(
2
)0()1()1(
)0()1()0()1(
22
2
)0()0()0(
2
2
rfquadratic
)cos(ˆ
)cos(ˆ
Waveplane .m.e Large
)(
ˆDriftorder st 1
0)(
Driforder th 0
)ˆˆ()ˆˆ(ˆ132
:
Gyromotion
)cos(ˆ)sin(ˆ)(
of . vari.freqlow
B
V
B)(v
B
E
EBVV :•
BEV
v
BEV :
)(
,
r
B
E
E
00E
E(t)
F
+ -
•B
+-
•B
E
EV
- +
peV
•B
EV
piV
(反 )
E
Ex
By
kz
μ ,
•
• SUMMARY OF PLASMA WAVES
(1) BO = 0
uncoupled
11210~
10~
1~
ccn
KeVT
TB
plasmasizedfinitetodue
ificwaves
longeiklawFor
.mod,
),.(
(2) BO = 0 : coupled
IA : hot electron –shield ion - wave
22peceu
cicePICIL ~22
22
2
2
)1( cepe
ce
pe
(3) Bo = 0
LH
UH
cs~vi
IA
EC
IC
RL
C
IAW
tev
tiv
pepe
pipi cs
pi
)( onlyonlyk //
k0.1
44
200
wLH=210wL
ceci
RP
vA
W
SAMS
vA
The total ohmic power per length
Trloss
abs
eRLRRPL
rdrLPLR
)(2)(
20
EJEenJ e
lost power radial loss only 1-D
TSOoeOo
Tee
euRJRnrJnerdr
eRRnEenrdr
R
R
)(2)(2
)(22
2
0
0
2
Thus )()( rJnrn Oo
(14.2.6)TizaoOeo eRJvDRnrdrrJen
R
)(2)(2 1
0
2
(14.2.10)
)13.2()( )(T(p) eTm pe
miz
e
Tiz
)15.2()(2
)(;
)14.2()(
)()(
)(
00
00)(
2
21
RR
r
rJrdrenrdrJI
rJnnenJ
RRD
m
e
Oeo
e
TOI
e
To
a
e
m
e
eic
T2
eAV
JAV
IVpower
a
O
IZ DR
v2
1
)4.2.14(
(discharge current, input)
)()(
)()(
1
1
' xJxJ
rrJdrrrJ
o
o
ERn e)(
)(1 RJR
/)(1 RRJ