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

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


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


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


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


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


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


Session 1

Flat fluorescent lamp for LCD backlight


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


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


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

Documents

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