先進電漿電源之發展現況 Current Status of Advanced Plasma ...™³世民-先進電...with Closed Loop Control (for Dielectric Film) Argon Flow O2 Flow Needs to be very close

TRUPLASMA HIGHPULSE SERIES, name name ■ CONFIDENTIAL

先進電漿電源之發展現況

Current Status of Advanced Plasma Source

陳世民 (David Chen)Tel: +886-3-666-1106; Mobile: [email protected] ; www.libra-tech.com.tw力寶來科技股份有限公司 (LIBRA TECHNOLOGY CORP.)地址: 新竹市東區關新路27號18樓之2

1

Libra Technology 1

mailto:[email protected]

http://www.libra-tech.com.tw/


Content

2

DC Power Supply Ignition Voltage Maximum Voltage/Current (Wider impedance range) Arc Management (Voltage/Current/Cross Detection) Low residual arc energy DC Pulse Power Supply

MF Power Supply Sinusoidal MF Power Supply Bipolar MF Power Supply

RF Power Supply High efficiency / Pure 50 ohm amplify CombineLine Technology / High accuracy at low power Arc management / Mach Box

High Power Impulse Magnetron Sputtering (HIPIMS) Power Supply What is HIPIMS? HIPIMS Technology HIPIMS Applications (Hard coating, Oxide Reactive Sputtering,

Semiconductor Trench Filling, Coatings on plastic webs or foils, CIGS coating, Passivation coating, Textile Coating )


Making a plasma

Exhaust

Input

Outpu

t

Ultra-High

Vacuum

pump

Input

Outpu

t

High

Vacuum

pump

Input

Outp

utRoughin

g pump

Ar O2

DC power

supply Substrate/

wafers

Cathod

e

Valve

s

Plasm

a

cloud

Anode

Target

• Pumps create vacuum in chamber

• Process gas enters• Voltage is applied with

power supply• Plasma Ignites• Plasma process is run

3


Sputtering

• Conductive or semi-conductive targets

• Target voltage ionizes gas (plasma)

• Target voltage (-) attracts gas ions (+)

• Gas ions bombard the target

• Bombardment vaporizes target atoms

• Vapor condenses on substrates (film)

Electron (primary)leaves (-) electrode

Primary electroncontinues toward (+)

secondary electron

All electronsattracted to (+)

Avalanche ofcollisions occurs

All ions (+) areattracted toward (-)

+

+ +

Electrons are thekey to ionization

Create ions and electrons:

e-+Ar Ar++2e-

dc power supply

vacuum pumps

pu

mp

exh

au

st

-

+

substrate

target

plasma

cloud

working gas

vacuum chamber

4


DC Magnetron Sputter

for conductive film

DC power supply

vacuum pumps

pum

p e

xhaust

substrate

targetplasma

cloud

working gas

vacuum chamber

NSSN

Magnets

5


Ion Plating (DC Bias)

vacuum pumps

pum

p e

xhaust

dc power supply-

+

substrate

target

plasma cloud

working gas

(500 V typ.)

vacuum chamber

N S

dc voltage supply (200 V typ.)

-

+

• Gas ions attracted to “growing” film

• Low energy bombardment hardens film

• Voids are filled• Surface is

smoother• Coefficient of

friction is reduced• Higher resistance

to wear

6


Mechanics of Ion Plating

Inert

Plasma

Cloud

+-

+-

0

0+

-

+++

DC

voltage

bias

+ -Compacted

hard film

Sputtered

atoms

Gas

ions

Growing

film

7


Power Characteristics - 1

8

TruPlasma DC 3000 Series (water cooled) power characteristic (with 1500 V ignition)

U

IImaxIn/2.50

Pmax

1000V

400V

1500V

Ignition Voltage : 1500 V

Maximum Voltage : 1000V

Maximum Current :

Power Current

20KW 50A

40KW 100A

60KW 150A


Materials

DC for conductors MF for semiconductors RF for insulators

Process Issue for Sputtering - Arcing

9


Arc Punch-through

10


Sustained Arc

11


Arc spot cathode, droplets at the substrate,

(copper) (copper)

Arcs Influence

12


Nature of an Arc

• An arc is a stable plasma discharge in a vacuum environment

• Charge carriers are electrons (generated from the hot spot) and ions from the plasma Current increase & Voltage drop

• Cause damage to the substrate, film, and target surface

What Causes Arcs?• Punch-through on an insulating layer is the

primary cause of target arcs• Occurrence of small areas of negative

plasma impedance• Local area of high electron emission on

insulating layers• mechanical damages on target surface

13


Arc Detection - Current Criteria (Imax)


14


Arc Detection - Voltage Criteria (dU)


15


Arc Detection - Voltage&Current Cross Detection Criteria


16

TRUPLASMA HIGHPULSE SERIES, name name ■ CONFIDENTIAL 17

UxI cross

detection enabled

In case of

“Restart into Arc” or

“Secondary Arc”

Current rises quickly

Voltage remains low

faster shutdown

prevents damage


Why Cross Detection ?


UxI cross detection combines the benefits of dU and Imax detection

dU enables very quick detection of arc events

Imax reliably detects secondary arcs (process start-up into a burning arc)

Imax does not trigger arc events in case of “false arcs” (voltage fluctuations

in the plasma)

First Arc vs. Secondary Arc reaction


TRUPLASMA HIGHPULSE SERIES, name name ■ CONFIDENTIAL19 2009-02-12 TE221vo

Generator

Power Supply

leadsL

Chamber1D

2D

SS

C

leadsL

C-D

SS

+

SS

Low residual Arc Energy level

Fast return to Iout = 0 enables fast restart

SS Serial Switch

D1 Freewheeling diode

D2 Bypassing diode

C Capacitor

C-D Discharge circuit


19


Arc Management without CompensateLine

20



Arc Management with CompensateLine

21



Arc Management with and without CompensateLine

22



Active Solution to Arcing

• In the event of an arc, reduce the energy delivered and respond quickly

• Prevent the buildup of energy at the surface

Breakdownvoltage

Time

Arc

Zero volts

Voltage

(acro

ss

the film

)

Charge-up rate of an insulating filmis a function of dielectric constant ofthe film, thickness of the film, andprocess current level.

Breakdown voltage is afunction of film thicknessand dielectric constant.

23


Active Solution to Arcing

Time

Arc

Zero volts

Voltage

(acro

ss

the film

)Reversing target voltagedischarges insulating film

BreakdownVoltage

24


Active Solution to Arcing – DC Pulse Power Supply


25


DC Pulse Single Cathode Reactive Sputtering

for Dielectric Film

Ex1: Si+2O+ SiO2

Ex2: 2Al+3O+ Al2O3

Problem Disappear Anode Problem not good for mass-

production

Argon FlowO2 Flow

Needs to be veryclose with fast valve(MFC too slow, need

more like piezo-electric valve at 2ms

speed)

Pump 1: Diffusion Pump (Ar + O2)

#BEAC11#E:\PHOTO_CD\IMAGES\IMG0007.PCD607116320842836238362836238362PB4011203602540

(-)

+

++

+

+

+

-

-

-

-

-

-

Ions

Pump 2:Getter Pump

(Al + O2)

-

Want to operate with slightexcess of O2 flow. Moresecondary electrons are

released as SiO2 is createdon target which effects

plasma density anddecreases voltage

XValve Controller

Setpoint

Feedback (FromP.S. or PEM)

26


DC Pulse Bias for Cathodic Arc Deposition

Output Voltage:

HV mode: Up to 1000 V

for discharge

LV mode: Up to 300 V

for deposition

27


MF Power for Dual Cathode Reactive Sputter

(for preventing disappear anode problem)

20 ~ 100KH, Sinusoidal MF Power

Supply: TruPlasma 3000

28


MF Dual Cathode Reactive Sputter

with Closed Loop Control (for Dielectric Film)

Argon FlowO2 Flow

Needs to be veryclose with fast valve(MFC too slow, need

more like piezo-electric valve at 2ms

speed)

Pump 1: Diffusion Pump (Ar + O2)

(-)

Ions

Pump 2:Getter Pump

(Al + O2)

XValve Controller

Setpoint

Feedback (FromP.S. or PEM)

+

+

-

-

-

+

+

-

-

-

(+)

Ex1: Si+2O+ SiO2

Ex2: 2Al+3O+

Al2O329


Dual Cathode Reactive Sputter – Sinusoidal MF Power Supply


30


Dual Cathode Reactive Sputter – Bipolar Power Supply


31


Reasons to Use RF power

• when processes you can’t do with DC

• Bi-directional ion movement

• Sputtering of dielectrics

• Voltage biasing of dielectrics

• Etching of dielectrics

• PECVD of dielectrics

• 10X - 100X greater ionization than DC

• More atomic disassociation of compound gasses (in the plasma state)

32


DC Capacitive Charge-up

Plasma cloud

- - - - - - - - - - - - - - - - - - - - - - - - -

+ + + + + + + + + + + + + + + + +

Electrical insulator

DC voltage source

Surface

charge

Gas ions+ ++

+

+

33


AC Capacitive Discharge

Plasma cloud

- - - - - - - - - - - - - - - - - - - - - - - - -

+ - - - + - - - - - + + + - + - - - - + - - - - +

Electrical insulator

RF voltage source

Reduced

surface

charge

Gas ions +++ + +

34


What is RF power?

AC frequencies above 20 kHz (audio)AC frequencies below 300 MHz (microwave)FCC RF frequency ranges Low frequency: 30 kHz - 300 kHz Medium frequency: 300 kHz - 3 MHz High frequency: 3 MHz - 30 MHz Very high frequency: 30 MHz - 300 MHz

Many people call 13.56 MHz “RF”

LF MF HF

FCC frequency classification

30k 300k 3M 30M

13.56M4.0M1.0M100k25kHz

2 M 27.12M 40.68M

VHF

35


RF Magnetron Sputtering for Dielectric Film

RF Power

vacuum pumps

pum

p e

xhaust

substrate

targetplasmacloud

working gas

vacuum chamber

NSSN

Magnets

36


DC Sputter with RF Voltage Bias

vacuum pumps

pu

mp

exh

au

st

dc power supply-

+

substrate

target

plasma

cloud

working gas

(500 V typ.)

vacuum chamber

N S

RF voltage bias

(200 V typ.)

-

+

37


RF Power Supply

Process

Chamber

RF Generator Matching Network

38


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 500 1000 1500 2000 2500 3000

Output Power, W

Efficiency Comparision (3 kW devices)

Apex

Sure Power

Paramount

SSM3000

Supplier 1

Supplier 2

Supplier 3

Hüttinger

TruPlasma RF Series 3000

Eff

icie

ncy c

on

ve

rsio

n

* Class D Amplify


Huettinger RF3000 achieve 80% power transfer efficiency : Green Energy

39



PowestagePredrive

PowerLoad

Power

predrive

loadP

P

PG

Measurement:HV 100V (no regulation)

abs(Γ)= [ 0 : 0.1 : 0.9]

Angle(Γ)= [-180° : 10° : 180°]

The power gain of the RF power stage is reduced in case the load

impedance is not identical to 50 Ohm. This effect results into inherent

reduction of the output power in case of sudden mismatch. This

reduction does not require any action of the module control and is

able to follow the fastest plasma fluctuations and events like arcs.

Power gain

Load impedance


Huettinger RF3000 special pure 50 ohm power gain characteristic

40

TRUPLASMA HIGHPULSE SERIES, name name ■ CONFIDENTIAL41 September 2011

50 point

50 point

In case of mismatch situations

(= deviation from 50 point),

it is possible that additional power

is delivered into the process.

If an impedance mismatch occurs

(= deviation from 50 point),

power delivery into the process is

always reduced.

Less power

More power

Less power Less power

Typical RF gain characteristic TRUMPF Hüttinger RF gain characteristicPowerPower

Comparison of RF gain characteristics


41



RF supply 11.5 kW

Phase 0°Class D

RF supply 21.5 kW

Phase 90°Class D

Plasma

Load

Absorber on heat sink

(cooling plate)

Forward power Pi

1 W .. 3000 W

PR reflected

power

Reflected power PR

Max. cont. 600 W

Matchbox

(auto/fix)tune to 50

50 RF cable

13.56 MHz

RF combiner

CombineLine

Load power PL= Pi-PR

50

CombineLine Technology : inherent robustness

allow Continuously output at 20% reflection


42


External clock signal control for two internal Class D power supplies allows

adjustment of phase difference between infeed power portions:

Very precise control for phase shift

Very fast reaction

Broad output power range:

1 W to 3000 W

Continuously high accuracy

(± 3W or ± 2% of set point

whichever is greater)

Load 50

RF supply 1

1.5 kW

Phase 0°+ΔφClass D

Absorber

50

CombineLine

1 3

4 2

Phase shift regulation mode: Accuracy at low power


43


Output control

Range 400 .. 3000 W :

Via DC source power

level control

(lower DC power lower RF output)

Range 1 .. 400 W :

Via phase shift regulation

Film deposition at very low power levels:

Very accurate power control

Excellent power stability for best

reproducibility results

(internal power supplies operate

at well-conditioned power level of 200 W)

Load 50

RF supply 1

1.5 kW

Phase 0°+ΔφClass D

RF supply 2

1.5 kW

Phase 90°-ΔφClass D

Absorber

50

CombineLine

1 3

4 2



44


Δφ = 0° 100%

Operation mode of two internal power supplies

stays at 150 W forward power each

Shifting of phase allows sweep of full range 300

W .. 1 W at high accuracy

(Excess power is lead into absorber)

High Accuracy < 1,5% demonstrated with actual

measurement (HATS standard)

Above 300 W adjustment is done via DC source

power control Energy efficiency

Δφ = 100°

Δφ = 160°

Internal power

supply output

(phase-shifted)

Internal power

supply output

(phase-shifted)

Resulting

Output

(super-

imposed)

Resulting

Output

(super-imposed)



45


An arc event is indicated if the reflected power level exceeds the defined threshold Pr [W].


Threshold Pr

= 1200 W

Arc Detection – Threshold detection of reflected power


46


An arc event is indicated if the power reflection factor exceeds the defined threshold Pr/Pi [%].


Threshold Pr/Pi

= 40 %


Arc Detection – Threshold detection of power reflection factor

47


An arc event is indicated if the reflected power rises faster than the defined slope value in [W/Tsample].


Slope ΔPr / (n*Tsample)

= 600 W / 1*Tsample

ΔPr/ sample = 400 W ΔPr/ sample = 1000 W

Arc event indication

No arc event indication

1 sample ≈ 100ns


Arc Detection – Slope detection of reflected power

48


An arc event is indicated if the power reflection factor rises faster than the defined slope value in [%/Tsample].


Slope Δ(Pr/Pi) / (n*Tsample)

= 30 % / 1*Tsample

Δ(Pr/Pi)/ sample = 15 %

Δ(Pr/Pi)/ sample = 35 %

Arc event indication

No arc event indication

1 sample ≈ 100ns


Arc Detection – Slope detection of power reflection factor

49


To clarify the keywords used in the parameter definitions, this figure introduces the most relevant ones.


Burst = Defined number

of pulses

Retry = Repetition of

burst

Pulse = Supression time + Pulse on time

Su

pp

ressio

n

tim

eP

uls

e o

n tim

e


Arc Reaction – Reaction keyword definitions

50


TruPlasma Match 1000/13 NEW Series : 0.5 sec match & smith chart



Summary of Sputtering

Materials DC Power for conductive target DC Sputter DC Sputter + DC Bias at substrate Ion Plating DC Pulse Power for conductive target DC pulse sputter MF or DC Pulse for semiconductor MF reactive sputter RF Power for insulators RF Sputter

If we want to get better film quality,

what is next solution? HIPIMS

Cathodes DC Single Cathode Conductive Film Sputter RF Single Cathode Dielectric Film Sputter DC Pulse Single Cathode Reactive Sputter for Dielectric Film Sinusoidal MF Dual Cathode Reactive Sputter for Dielectric Film Bipolar MF Dual Cathode Reactive Sputter for Dielectric Film

52


What is HIPIMS?

HIPIMS = High Power Impulse Magnetron Sputtering

53

DC Sputtering

Pulsed DC

106

105

104

103

102

Po

we

r [W

]

Time

HIPIMS

DC – always on

Pulsed DC – mostly on

HIPIMS – mostly off


What is HIPIMS?

54

DC, pulsed DC or RF generators have output power levels in kW.

HIPIMS provides peak power output levels in MW (Megawatt).

… however HIPIMS is 99 % off MW only for 1 % of the time.

… so average HIPIMS power is also in kW.

10 ms


HIPIMS Technology

55

HIPIMS acts as large area ion source (ions of the sputter target material)

Ionization density up to 95% (controllable via pulse repetition rate and duration)

Can etch with these ions (high bias)

Can grow dense coatings with these ions (low or no bias applied to substrate or specimen)

TruPlasma

Highpulse 4001

TruPlasma Bias

(specialised for

HIPIMS application)


HIPIMS Technology

Ionization of Sputtered Atoms

56

A.P. Ehiasarian, 2004 Society of Vacuum Coaters

Higher pulse current

more ionization.

Need > 100 µs pulse duration to see much ionized material.

Pulse longer than 200 µs not increase ionisation any moreControl of ionization percentage

via pulse current and time.


The basic HIPIMS power supply comprises

• DC Charging power supply• Storage capacitors• Control switches• Pulse shaping inductors

Circuit From : “Ionized physical deposition (IPVD) : A

review of technology and applications”, U. Helmersson, M

Lattemann, J. Bohlmark, A.P. Ehiasarian, J.T.

Gudmundsson, Thin Solid Films, 513, Issue 1-2, (2006), 1-

24

HIPIMS Technology


HIPIMS Technology

Pulse Current, Pulse Length & Pulse Frequency

58

Fix the pulse length and pulse current to give us required ionization level.

Energy in a pulse is

Epulse

≈ 0.5 x Vpulse

x IMAXpulse

x pulse length

Average power is

Pavg

= Epulse

x Pulse frequency

The average power has a maximum level determined by

the cooling capacity of the magnetron

the rating of the power supply.


TruPlasma Highpulse Series 4000 : Technical Specification

59

2 … 1K Hz



HIPIMS Application

Typical Applications

60

Decorative Coating

Hard Coating for machining tools Semiconductor Applications

Eco-textiles

Performance textiles Functional textiles

Smart textiles

Textiles Coating


61

Droplets visible on surface

TruPlasma ARC 3000

Droplet free film

TruPlasma Highpulse 4000

HIPIMS for Droplet-free deposition SEM TiN IMAGES

with TruPlasma Highpulse Series 4000

vs


Ions make coatings denser

Ideal case is lots of ions in

plasma

(>20% of coating material)

HIPIMS hard coatings show

much better wear resistance

HIPIMS for Improved wear resistance in Hard-Coating Applications


62

A.P. Ehiasarian et al. /

Thin Solid Films 457 (2004) 270–277


HIPIMS for Semiconductor Applications – Trench Filling

63

Semiconductor surface structures

smaller, so it is harder to fill

trenches.

Cannot control the arrival angles of

neutral atoms/particles

Can control the arrival angles of ions

HIPIMS generates highly ionised

particle flux, which can be directed

via biased substrate

Controlled angles give much better

deposition down trenches or holes.

Cu-filled trench produced with

HIPIMS, by Kouznetsov et. al.

BIAS power

applied to

substrate

Usual sputter trench filling.



HIPIMS for CIGS solar cells

HIPIMS power deposition process

64

Normal DC or pulsed DC for Cu

sputtering in CIGS process

HIPMS was used as drop-in

Good ionisation of Cu atoms

was observed (PEM graph)

(Cu lines are more prominent than Ar lines in spectrum)

Images and data courtesy of

DayStar Technologies

HIPIMS on 1.5m Rotatable Magnetron

0

1000

2000

3000

4000

5000

6000

200 300 400 500 600 700 800 900 1000

wavelength (nm)

PE

M i

nte

ns

ity

HIPIMS

DC

Metal/ Metal ion peaks (Cu,

In, Ga)Argon peaks


HIPIMS for CIGS solar cells

HIPIMS power deposition process

65

Larger grains favorable

for solar cell efficiency

Realised cell conversion

efficiency CE = 13.1%

As a first step, it was shown

that a solar cell can be made

with HIPIMS

Next step: Optimisation of

HIPIMS effects on film

properties

Images and data courtesy of

DayStar Technologies

500 nm

CIGS by

HIPIMS

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0 0.1 0.2 0.3 0.4 0.5 0.6

Voltage (V)

Cu

rren

t (A

)

Voc = 563 mV

Jsc = 33 mA/cm2

FF = 69.9 %

CE = 13.1 %

Area = 0.43 cm2


HIPIMS for Reactive Sputtering Applications


66

HIPIMS significantly changes the

hysteresis loop of reactive

sputtering.

The DC case does not allow high

rate sputtering of the oxide.

if HIPIMS is used for the same

process then the target is kept

metallic at significantly higher

oxygen flows, and most

importantly Aluminium Oxide

can be sputtered at much

higher rates than for the DC

case. Wallin and Helmersson believe that this improvement

is due to the high peak target currents acting to keep

the target surface free of reaction productions

(poisoning). Target poisoning between pulses is

minimal no plasma to activate these reactions.

DC hysteresis curve for Aluminium

reactively sputtered in Argon and OxygenE. Wallin, U. Helmersson, Thin Solid Films (2007),

doi:10.1016/j.tsf.2007.08.123


HIPIMS coatings on plastic webs or foils (1)

67

HIPIMS produces low substrate heat load for the same input average power

Delivering the power as pulses

peak power can be enormous (MW) … while the average power is still within

the cooling limit of the magnetron (kW)

Factor of 3.5 and 10 times lower in HIPIMS mode compared to continuous DC

and pulsed DC modes

CFUBMS system (UDP450) Teer Coatings Ltd.

300 x 100 mm unbalanced magnetrons

Target material: Titanium

TruPlasma Highpulse 4001, pulses up to 1MW

(1kA, 1kV), average power up to 2kW, pulse

frequency up to 1 kHz

Normalised thermal energy loading rates for deposition at 1nm/sec


HIPIMS coatings on plastic webs or foils (2)

68

Operating the HIPIMS power supply with many pulses of lower power

keeps the average power high

maintains a good deposition rate

has very low heat load on the substrate

Film deposition on plastic foils is possible with HIPIMS

advantage over pulsed DC or DC sputtering processes

Reference: HIPIMS Magnetron Sputtering onto plastic webs P. Barker1, G West1, D. Ochs2, P. Ozimek3, J Bradley4, P. Kelly1, A. Mishra1, A.G.

Spencer5 1 Manchester Metropolitan University, UK 2 TRUMPF Hüttinger GmbH + Co. KG, Freiburg, Germany 3 TRUMPF Hüttinger Sp. z.o.o., Zielonka, Poland, 4 Liverpool University, UK 5 Alacritas Consultancy Ltd.,Leicestershire, U.K.


HIPIMS for Textile Coating

Low process temperature

69


Stronger effect Medium effect Weaker effectAg Cd AlBi Pt CoCu Si CrMo Ti MgTl Mn

PbZn

Application I： Antibacterial textile

70


Metallic Coating Metallic Fiber/Particle

Application II：EMS textile

EMS textileElectromagnetic Shielding

Shielding Effectiveness (SE) =The ratio of power received with (P1) andwithout (P2) a material present for the same incident power, 20 log P1/P2

SE↑Content of particle/fiber↑ or Coverage ratio ↑

SE↑ Conductivity ↑ (Continuous structure)

FTTS-FA-003 Specified Requirements of Electromagnetic Shielding Textiles.

71


Application III：Far-IR textile

Passive heating Active heating

Surface Heating

Wire Heating

72


Other applications enabled by HIPIMS power deposition processes

73

Improved protection of HIPIMS surface-treated carbon steel against corrosion

Improved cutting performance (~10%) with tools pre-treated by HIPIMS

Low substrate temperature level enables foil coating applications

Surface texture control in TCO and SiN passivation film depositions

…

Sheffield Hallam University SHU


The End

74

Documents

先進電漿電源之發展現況 Current Status of Advanced Plasma ...™³世民-先進電...with Closed Loop Control (for Dielectric Film) Argon Flow O2 Flow Needs to be very close