Transcript What is Plasma

PVD (Physical Vapor Deposition )
Technology
tsmc FAB 14
吳佳俊
© 2010 TSMC, Ltd
Outline
 What is Plasma
 Convention PVD Process (DC plasma)
 DC Plasma PVD bottle neck
 What is RF ( Radio frequency )
 PVD Chamber H/W Evolution
 Metal line process overview
 tsmc introduction
 EE responsibility
Q&A
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What is Plasma ?
 電  Electrical Particles
 漿  Collective motion
 It contains highly reactive gas species
 It emits light  glow (O2->whitish-blue, N2->pink)
 It is driven by electric energy  electric field
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Plasma Components
 Created by current through a gas
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Gas is partially ionized
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Quasi-neutral plasma

Nearly equal numbers of positive (
) and negative (
)
Basic Plasma Concept
 Ionization
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Initially, very few electrons are present in neutral gas

The electrons are accelerated by energy input
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Newly produced electrons accelerate and ionize more neutrals
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Ionized avalanche happened

Equi-potential cloud plasma is formed
Basic Plasma Concept
 Excitation-Relaxation
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Light is emitted
Basic Plasma Concept
 Dissociation
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When an electron collides with a molecule with enough energy
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Break its bonding energy into apart
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Much less energy than ionization
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Much higher dissociation rate than ionization
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DC Plasma
 Initiation of The Plasma
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Plasma is formed when an avalanche of ionization occurs

This results in a sea of positive and negative charged particles

The gas into plasmas transition involves going from insulating
medium to conductive medium
Basic Plasma Concept
 Steady plasma source

Energetic electron (Plasma type)
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Appropriate collision (Recipe)
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Plasma sustain (Geometry design)
PVD
Dry-ETCH
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HDP-CVD
PVD(Physical Vapor Deposition) Process
(DC plasma Deposition)
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Sputtering
 Momentum transfer will dislodge surface atom off
 About 70% energy converts to heat
 About 25% energy generates secondary electrons
 Secondary electrons ionize Ar
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DC Magnets Sputtering
 Film Uniformity
 High target utilization
 Full face erosion
 Plasma ignition & sustaining
 Step coverage
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DC Magnets Sputtering
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Convention PVD (DC Plasma)
 Target (Metal source)
 Plasma
 Gas
 Pump
 Pedestal
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Convention PVD Process
 Ion generated & toward a target
 Atoms sputter from target
 Sputtered atoms traverse to substrate

Condense

Nucleated
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Form a film
-V
Pedestal
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Film Growth Overview
 Formation of isolated nuclei
 Island formation
 Formation continuous film grain boundaries
 Grain growth
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DC Sputtering Deposition Schematic
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DC Plasma PVD Bottle Neck
 Aspect Ratio (h/w)
 Step Coverage
W
h
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SiO2
Collimator PVD
 Lower deposition rate
 Potential Particle issue
 Shorter PM cycle
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Long throw PVD
 Lower deposition rate
 Worse film uniformity
 Shorter PM cycle
L
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PVD(Physical Vapor Deposition) Process
(RF plasma Deposition)
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What is RF ?
 AC frequencies
RF
audio
20 kHz
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microwave
300 MHz
Radio frequency
13.56MHz
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Radio
Frequency
Why need to use AC Plasma ?
 Step Coverage Ration
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DC Biasing of RF
 RF power couples through the wafer like a
capacitor
 On-average, the wafer is biased negative
(attracts ions)
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AC Capacitive Discharge
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Bias Effect
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What is RF Power?
Existing metrology only measures in 1-D:
Power (watts)
However we know: Watts = Volts * Amps * cos(
and Power is actually a 3 - D quantity:
phase
current
voltage
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)
RF Power
 Forward Power

Power from RF generator
 Reflected Power

Power return to RF generator
 Load Power

Power consumed by load
Direction Coupler
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Impedance (Z)
 Made up of two parts

Resistance

Reactance (Capacitive & Inductive)
 Most RF generator are designed to operate into
a 50  load
 Plasma impedance ZL dependent on Power
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Gas pressure and chemistry

Power level and frequency
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Chamber materials and geometry’s
Maximum Power Theorem
 Maximum power when ZS = ZL
 RF generator ZS = (50  j0)
 ZS  ZL  Reflected power increased
 RF tuner is required to transform ZS = ZL
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RF Matching Network
 Manual match
 Auto match

Air capacitor (for low power / fast response)
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Vacuum capacitor (for high power / low response)
 Fixed match

The most fast response / acceptable reflected power at certain
VSWR
 Switching match (fast response)
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IMP (Ion Metal Plasma) Chamber
 DC RF source generate
Medium density Plasma
 Add coil DC
 Coil sputtering,
blocking capacitor
 Increase pedestal bias
potential
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Incident Angle Distribution
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PVD Technology Trend
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SIP Technology
 Self ionized Plasma

Sputter discharge in which the dominate ionized
species is from the target

Higher ionization rate and enough self-sputter
yield to sustain plasma without Ar gas
 Plasma Characteristics
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High power

Low pressure
SIP Process
 Large wafer to target spacing

Leads to “long-throw” directional trajectories for neutral
 Unbalance Magnet

Control ion trajectories
 Cooled, biased substrate
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SIP EnCoRe Cu
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SIP EnCoRe Cu
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PVD Technology Evolution
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Metal Line Process Overview
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AMAT EnCoRe Barrier/Cu Seed
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AMAT EnCoRe Barrier/Cu Seed
PVD 3
(TaN)
PVD 4
(Cu)
Ta
Ch D
(PC II)
Ch F
(Degas)
SWLL
B
TaN
FI
LP 2
SWLL
A
PVD 2
(TaN)
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PVD 1
(Cu)
Ch E
Ch C
(PC II) (Degas)
LP 1
ECP (Electric Chemical Plating)
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NVLS Sabre ECP
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NVLS Sabre ECP
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CMP (Chemical Mechanical Polish)
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AMAT Reflexion CMP
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Introduction of tsmc
tsmc (Taiwan Semiconductor Manufacturing Company)
 成立於1987年
 董事長兼總執行長 張忠謀 博士
 專業積體電路製造

二座 12“ 超大型晶圓廠 (GIGA fab) (fab 12 & 14)

四座 8“晶圓廠 (fab 3, 5, 6 & 8)

一座 6“晶圓廠 (fab 2)
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二家海外子公司 (美國WaferTech & 台積電(中國))
照明、太陽能(新事業群)
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The Responsibility of Equipment Engineer
 設備的醫生

預防保養 (健康檢查)

Trouble shooting (治療疾病)

防範未然 (上工治未病,史記 扁鵲倉公傳)
 Innovation
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Productivity

Cost
設備工程師招募
今年底前可投入職場者 (畢業& 役畢)
[email protected]
[email protected]
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Q&A
Thanks You
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Home Work
 What is plasma and its components?
 What are the benefit of DC magnets sputtering?
 How many types do PVD chambers have?
 How many types do RF matching have?
 Please description the process flow and
purpose in barrier/Cu seed deposition.
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