pattern dependent characterization of copper interconnect

Duane Boning - ICMTS 2003 1 MIT-MTL

Pattern Dependent Characterizationof Copper Interconnect

Prof. Duane Boning

Massachusetts Institute of TechnologyMicrosystems Technology Laboratories

http://www-mtl.mit.edu/Metrology

ICMTS Tutorial, March 2003


Copper Interconnect Dual Damascene ProcessDeposit dielectric stack; Pattern trenches & vias

Barrier deposition; copper electroplating

CMP

SiO2

SiO2

Si3N4 Etch Stop

SiO2

SiO2

SiO2

Cu

TaN

■ Electroplating❏ “Superfill” used to fill

narrow trenches and vias ❏ Ideally: plated surface

nearly flat

■ Copper CMP❏ Multistep process to

remove bulk copper and barrier metal

❏ Ideally: polished surface nearly flat • no loss in copper wire

thickness• flat for next level

Cu Lines

Repeat for multiple levels of metal


Copper Interconnect Problems■ Polishing stages: bulk polish, barrier polish, and overpolish

CMP Process and Problems

Oxide

Oxide

Dishing

Field OxideLoss

Erosion

Non-uniform plating

Oxide

CMP

Overpolish

Evolving Surface Profile


Electroplating/CMP Characterization Methodology

Electroplating Process■ Fixed plating recipe

Model ParameterExtraction

■ Plating: Measure step height, array bulge/recess and field copper thickness

■ CMP: Measure dishing, erosion and field copper thickness

Calibrated ECD Pattern Dependent Model

■ Plating: prediction of step height, array height, copper thickness and local pattern density

■ CMP: prediction of clearing time, dishing and erosion, final copper line thicknesses

Chip-LevelSimulation

Product Chip Layout

Electroplating/CMPTest Wafers

CMP Process■ Fixed pad, slurry, process

settings (pressure, speed, etc)■ Variable polish times

Calibrated Copper Pattern Dependent

Model


Outline■ Background

❏ Pattern dependent effects in plating and CMP

■ Copper CMP Characterization❏ Polishing Length Scales❏ Test Structure and Mask Design

• Single Layer Test Structures and Mask Design• Multilevel Test Structures and Mask Design

❏ Measurements and Analysis❏ Design Rule Generation❏ Chip Scale Modeling

■ Copper Electroplating Characterization

■ Conclusions


Copper CMP Pattern Dependent Effects

Oxide

Dishing Erosion

Copper

0 200 400 600 800 1000 1200 1400 1600−0.24

−0.2

−0.16

−0.12

−0.08

−0.04

0

Scan Length (um)

Rel

ativ

e H

eig

ht

(um

)

0 200 400 600 800 1000 1200 1400 1600−0.24

−0.2

−0.16

−0.12

−0.08

−0.04

0

Scan Length (um)

Rel

ativ

e H

eig

ht

(um

)

Erosion

Dishing

Erosion

Dishing

Sample Profilometer Scans

Line width = 1 µmLine space = 1 µm

Line width = 9 µmLine space = 1 µm


Polishing Length Scales

FieldArray Structure

AnotherArray Structure

Oxide

Dishing

Rel

ativ

e T

hick

ness

(Å)

Scan Length (µm)SEM Cross Section(0.5µm wide line)

mm Range

~100µm Range

~1µm RangeInitial Copper Polish

Barrier/Overpolish

■ Three Polishing Length Scales:❏ ~2mm range: copper bulk polish❏ ~100µm range: erosion profile❏ ~1µm range: dishing profile


Dishing and Erosion Test Structures

Isolated Line Array Region

Line width/line space mark

500mm

50mm 2mm

2mm

1.0 1.0/2.0

500mm

IsolatedLine

DummyLine

ArrayRegion

0.5/4.5

Electrical

Electrical∆V

∆V

50mm2200mm

2160mm

Physical Test Structure Electrical Test Structure

Region

Measurement

Typical erosionprofilometry scan Measurement

❏ Profilometry: captures surface height over long scans❏ Electrical measurements: extract line thickness by probing


Dishing/Erosion Array Test Structures

(a) (b) (c)si

ngle

loop

loop

w/ d

umm

y

50%

den

sity

arr

a

(d)

■ Three Regions: b) Single loop: isolated linec) Small array: loop with surrounding dummy linesd) Large array: multiple taps along length of the array

■ Electrical Sampling: ❏ Each tap is a Van der Pauw structure: measure resistance❏ Uniform sampling: e.g. every 100 µm❏ Edge sampling: place more taps near the transition region


Copper Thickness Extraction ProcedureE-TestLineResistance

Line WidthCorrection

CopperThicknessExtraction

CopperThickness

Physical

PhysicalVerification

R

SEM+Profile+Optical

W+∆W

R -> TM TM

Oxide

TM

TL

TL

Copper

W

Barrier

Layer

Simplified Profile

■ R is measured line resistance■ Rs (ρ/t) is sheet resistance■ t is the thickness of a line■ ρ is the resistivity of copper■ L is the length of a line■ W is the width of a line.■ RCu is resistance due to copper

■ RL is resistance due to liner

■ ρL is the resistivity of liner

or by re-arranging variables (1)

and

(2)

(3)

R Rs LW-----×= t ρ

R---LW-----×=

RCuρCu L×

TM TL–( ) W 2TL–( )×----------------------------------------------------------=

RLρL L×

2TM TL×( ) W 2TL–( ) TL×( )+--------------------------------------------------------------------------------=

TMρCu

R---------- L

W 2TL–( )--------------------------× TL+=


Additional Structures

Metal 1Metal 2

Top Down View Cross Sectional View

Split Combs Solid Plate

100µm

100µm

Cross Section

Oxide Fill

Cu

Oxide

Slotting

Capacitance

Area

Top Down View

100µm

1000µm

Metal 2Metal 1


Single Layer Mask Designs

■ Single-level mask: electrical and physical test structures.■ Key pattern factors: density and pitch and/or linewidth and linespace.■ Structure Interaction: structure size and floor planning.

PITCH BLOCKS

DENSITYBLOCKS

DENSITYBLOCKS

15mm

15mmA. First Generation Mask(“SEMATECH 931 Mask”) B. Second Generation Mask

20mm

20mm

PitchStructures

DensityStructures

AreaStructures


Single Layer Surface Profiles and Trends

0 500 1000 1500 2000 2500

−1200

−800

−400

0

0 500 1000 1500 2000 2500

−1200

−800

−400

0

0 500 1000 1500 2000 2500

−1200

−800

−400

0

5.0µm/5.0µm

50µm/50µm

1.0µm/1.0µm

Isolated

Scan Distance in µm

Surface Profiles (in Å)

Lines

ErosionDishing

Lw/Ls

Lw/Ls

Lw/Ls

ErosionErosion

DishingErosion

Dishing

Array Region

Dishing

Dishing

FineFeatures

MediumFeatures

LargeFeatures


Extracted and Physical Copper Thickness

10 30 50 70 900

0.2

0.4

0.6

0.8

1

10 30 50 70 900

0.20.40.60.8

1

10 30 50 70 900

0.20.40.60.8

1

o = Extracted* = Physical

Metal Density (%)(for fixed pitch of 5µm)

Rem

aini

ng C

u T

hick

ness

(µm

) 300 sec. Polish Time (~11% Overpolish)

Metal Density (%)(for fixed pitch of 5µm)

Rem

aini

ng C

u T

hick

ness

(µm

) 270 sec. Polish Time (0% Overpolish)

330 sec. Polish Time (~22% Overpolish)

❏ Good correlation between extracted thickness and physical data.

❏ Clear trend of total remaining thickness is shown from the electrical data.


Analysis: Dishing and Erosion in Copper CMP

240 270 300 330 3600

500

1000

1500

2000

2500

0 50 100 150 2000

500

1000

1500

2000

2500

Dis

hing

(Å)

Polish Time (sec.)(270 = “just cleared”)

Dis

hing

and

Ero

sion

(Å)

o = Dishing+ = Erosion

Pitch Values (µm)(for fixed 50% metal density)

Dishing and Erosion Dependencies on Polish Time and Pitch

300 sec. Polish Time (~11% Overpolish)

5µm Pitch3µm Pitch

20µm Pitch

50µm Pitch

100µm Pitch

150µm Pitch200µm Pitch

10µm Pitch

■ Profilometry surface scan for dishing and oxide thicknessmeasurement for erosion.

■ Constant dishing after initial transition for smaller pitch structures.


Multilevel Process Sequence and Pattern Problems

Metal 1

Metal 2

Oxide

Oxide M1 Copper Lines

M2 Recess

M2 Remaining

As Dep.Oxide Profile

Oxide

Oxide


ThicknessOxide

Metal 2

Oxide

Oxide

1. M1 Polish

2. M2 Oxide Deposition

3. M2 Cu Deposition

4. M2 Polish

Metal 1


Multilevel Copper CMP Test Mask Design■ Multi-level mask: M1, Via, and M2

❑ electrical and physical test structures■ Single level effects: Layout factors on M1 to

study creation of topography❑ Density❑ Pitch (Line Width & Line Space)

■ Multiple metal level effects: Overlay M2 structures to study topography impact

20mm

20mm

Metal 1 Metal 2

Multi-Level Mask

Metal 2Metal 1


M1 Structure Design Space M1 Structure Design Space (in µm): < P2D50 = Pitch of 2 and Density of 50% >

LWLS 0 0.18 0.25 0.5 1 1.5 2 3 4 5 7 9 10 50 90 1000 D100

Solid0.18 P0.36

D500.25 P0.5

D500.5 P1

D50P2

D671 P2

D50P4

D75P6

D83P10D90

P51D98

P101D99

1.5 P2D33

2 P4D50

3 P4D25

P10D70

45 P6

D17P10D50

7 P10D30

9 P10D10

10 P20D50

P100D90

50 P51D2

P100D50

90 P100D10

100 P101D1

P200D50


Multilevel CMP Test Structure Design

Half Overlap Structure

Mask Layout

20mm

20mm

Metal 1: BlueMetal 2: Magenta

Arrays M2 Bond

M2 Bond

M1 Bond

M1 Bond

Iso.Lines

Pad (Top)

Pad (Bottom)

Pad (Top)

Pad (Bottom)

(“SEMATECH 954 Mask”)

■ Multi-level mask: M1, Via, and M2 with electrical and physical test structures.

■ Layout factors: Line width/line space combinations

■ Focus: Multi-level pattern effects■ Overlap structures: direct, half, and dual


Direct Overlap: Structure

Metal 1 Metal 2

Oxide

Oxide

M1 BottomPad

M1 TopPad

M2 TopPad

M2 BottomPad

CrossSectionalView

TopDownView

Metal 2

Metal 1


Direct Overlap: Data Analysis

OxideAs Dep.Oxide Profile

Metal 2

Metal 1Oxide

0.5

0.6

0.7

0.8

−2000

−1000

0

−500 0 500 1000 1500 20000.5

0.6

0.7

0.8

M2

Rem

ain.

Thi

ck. (

µm)

M2

Rec

ess

M1

Rem

ain.

Thi

ck. (

µm)

µm

M2: Surface Scan

M2: Electrically Extracted


No Overlap

Overlap

Iso. Lines

Iso. Lines

(Å)


Multilevel Half Overlap Structure


Metal 1 Metal 2

Oxide

Oxide

M1 BottomPad

M1 TopPad

M2 TopPad

M2 BottomPad

CrossSectionalView

TopDownView

Metal 2

Metal 1


Half Overlap: Erosion to Erosion

0.5

0.6

0.7

0.8

−2000

−1000

0

0 500 1000 1500 2000 25000.5

0.6

0.7

0.8

Iso. Lines

Over OverStruct. Oxide


M2: Surface Scan


µm

Ref.

Oxide

Oxide


M2

Rem

ain.

Thi

ck. (

µm)

M2

Rec

ess

M1

Rem

ain.

Thi

ck. (

µm)

(Å)

Metal 2

Metal 1


Half Overlap: Dishing to Erosion

0 500 1000 1500 2000 2500 3000−2000−1500−1000

−5000

0 500 1000 1500 2000 2500 3000−2000−1500−1000

−5000

M2 Profile (Å) No OverlapRegion Over

Oxide0.5µm Lw/ OverStruct.

M1 Profile (Å)

Scan Distance (µm)

0.5µm Ls

50µm Lw/50µm Ls

M2 Array

DishingDominant


Half Overlap: Erosion to Dishing/Erosion

0 500 1000 1500 2000 2500 3000−2000−1500−1000

−5000

0 500 1000 1500 2000 2500 3000−2000−1500−1000

−5000

Dark bandindicates dishing

M2 Profile (Å) No OverlapRegion Over

Oxide5µm Lw/ OverStruct.

M1 Profile (Å)

Scan Distance (µm)

5µm Ls

1µm Lw/1µm Ls

M2 Array

ErosionDominant


Dual Overlap: Structure

Oxide

Oxide


Metal 2

Metal 1

Metal 1

Metal 2

M1 BottomPad

M1 TopPad

M2 TopPad

M2 BottomPad

CrossSectionalView

TopDownView


Dual Overlap: Data Analysis

0.5

0.6

0.7

0.8

−2000

−1000

0

0 500 1000 1500 2000 2500 30000.5

0.6

0.7

0.8

OverStruct.1

M2 Electrically Extracted

Ref.

M2: Surface Scan


µm

OverStruct.2

Iso. Lines

Oxide

OxideMetal 2

Metal 1

M2

Rem

ain.

Thi

ck. (

µm)

M2

Rec

ess

M1

Rem

ain.

Thi

ck. (

µm)

(Å)



Multilevel Electrical Impact: M2 Line Thickness

■ Metal 2 thickness (0.5 µm line/space) as function of space from the edge of the metal 1 array (3 µm line/1mm sapce)

■ Change in resistance of a 0.5 µm mtetal 2 line/space structure at a transition in metal 1 density

Lakshminarayanan et al. (LSI Logic), IITC 2002.


Design Rule Generation

Lakshminarayanan et al. (LSI Logic), IITC 2002.


Modeling of Pattern Effects in Copper CMP

bulk

OxideErosion

MetalDishing

Stage 1 copperremoval

Stage 2 barrierremoval

Stage 3

over-polish

■ Approach: Apply density/step-height model to each stage in the copper polish process

■ “Removal Rate” Diagrams:❑ Track RR for metal and oxide

during each phase■ Approximation: neglect barrier

removal phase


Pattern-Density / Step-Height Effects

■ For large step heights: ❒ step height reduction goes as

1/pattern-density

■ For small step heights (less than the “contact height”): ❒ height reduction proportional

to height❒ height decays with time constant τ:

H t( ) H0e t τ⁄–=

H

tdd H t( ) 1

τ---H t( )–=

tdd H t( ) K

ρ----–=td

dH

Step HeightHc

Wafer

Wafer

CMP Pad

CMP Pad

Hc

X

PL

■ Calculate effective density by averaging local pattern densities over some window/weighting function

EffectiveDensity MapOver Chip

Ouma et al., IITC ‘98;Smith et al., CMPMIC ‘99Grillaert et al., CMP-MIC ‘98.


Chip-Scale CMP Simulation

0

500

1000

1500

2000

Cu Dishing after step 2 polish

50 100 150 200 250 300 350 400 450 500

100

200

300

400

500

600

700

Dishing after step two

RMS Error = 155 Å

Å

0 5 10 15 20 25 30 35 40 450

50

100

150

200

250

300

Site number

Dis

hin

g (

A)

Data Model

Site number

Dis

hing

(Å)


Outline■ Background

■ Copper CMP Characterization

■ Copper Electroplating Characterization❏ Definitions❏ Test Structure and Measurement Plan❏ Trend Analysis❏ Chip Scale Modeling❏ Integrated Plating/CMP Chip-Scale Modeling

■ Conclusions


Copper Electroplating Non-UniformitiesIsolatedLine

Array Region

Conventional Fill Super Fill(Bottom-Up Fill)

■ Isolated line and array region are recessed

■ Isolated line sticks up and array region is bulged


Electroplating Pattern Dependent Effects

0

Sample Profilometer

Oxide

SH

AH

0

Fine Line Large Line Fine Line Large LineFine Space Large Space Medium Space Fine Space

AH

AH

SH

AH: Array Height SH: Step Height

SH

AH

Scans


Measurement Plan and Sample Profile Scan■ Profile scans taken across each line/array structure

Isolated Line Array Region

Thickness Measurement

Bulge

Zoom

Recess

Step Height

Step Height

Step Height(Isolated Line)

(Isolated Line)

(Array Line)

into array

Superfill

Conformal Fill

Test Mask

X X

Profile Scan


Electroplated Profile Trends: Pitch Structures

0 1000 2000 3000

−5000

0

5000

2um/2um

0 1000 2000 3000

−5000

0

5000

5um/5um

0 1000 2000 3000

−5000

0

5000

10um/10um

0 1000 2000 3000

−5000

0

5000

20um/20um

0 1000 2000 3000

−5000

0

5000

50um/50um

0 1000 2000 3000

−5000

0

5000

100um/100um

0 1000 2000 3000

−5000

0

5000

0.25um/0.25um

0 1000 2000 3000

−5000

0

5000

0.3um/0.3um

0 1000 2000 3000

−5000

0

5000

0.35um/0.35um

0 1000 2000 3000

−5000

0

5000

0.5um/0.5um

0 1000 2000 3000

−5000

0

5000

0.7um/0.7um

0 1000 2000 3000

−5000

0

5000

1um/1um

Hei

ght (

Å)

Trace Length (µm)

Lw/Ls

Hei

ght (

Å)

0.25/0.25µm 0.35/0.35µm0.3/0.3µm

0.5/0.5µm 1/1µm0.7/0.7µm

2/2µm 10/10µm5/5µm

20/20µm 100/100µm50/50µm

Superfill

ConformalBehavior

Behavior


Step Height Data Analysis

10−1

100

101

102

−6000

−4000

−2000

0

2000

10−1

100

101

102

−6000

−4000

−2000

0

2000

Line Width (µm) - Log Scale

ArrayLine

IsolatedLine

LW

Step

Hei

ght (

Å)

Step Height vs. Line Width

■ Trends• SH depends on line width: near zero or positive (superfill) for small features

and becomes more conformal as line width increases■ Saturation Length: fill becomes fully conformal and SH = Trench Depth• Line width LW

= 10µm

0.5µm

Copper

Oxide 3µm 10µm

d

d

NarrowTrench

WideTrench

MediumTrench

Step Height Behavior


Array Height Data Analysis

10−1

100

101

102

−4000

−2000

0

2000

4000

6000

■ Trends• Positive (superfill) for small features, and becomes negative (conformal),

and saturates to field level as line width increases■ Saturation length: fill becomes fully conformal and AH = 0Å• Line width LW

= 10µm

Line Width (µm) - Log Scale

LW

Arr

ay H

eigh

t (Å

)

Array Height vs. Line Width

0.3µm 5µm 20µmOxide

NarrowTrench

WideTrench

MediumTrench

Array Height Behavior

Copper


SH and AH vs. Line Space

■ Trends• Line space dependency for SH and AH is similar to line width dependency

■ Saturation length: similar value is observed for line space• Line space LS = 10µm

Array Height vs. Line Space

10−1

100

101

102

−4000

−2000

0

2000

4000

6000

Arr

ay H

eigh

t (Å

)

LS

10−1

100

101

102

−6000

−5000

−4000

−3000

−2000

−1000

0

1000

2000

LS

Step

Hei

ght (

Å)

Step Height vs. Line Space

ArrayLine

Line Space (µm) - Log ScaleLine Space (µm) - Log Scale


Transition Length Scale in Electroplating■ Plating depends on local feature (feature scale) and nearest

neighbors within 2-5µm range

720 730 740 750 760 770 780−1000

0

1000

2000

2720 2730 2740 2750 2760 2770 2780−1000

0

1000

2000

700 750 800 850−4000

−3000

−2000

−1000

0

2650 2700 2750 2800−4000

−3000

−2000

−1000

0

Arr

ay H

eigh

t (Å

)

Array Height Profile Scans

Right Edge

Left Edge

~5µm

~5µm

Right Edge

Left Edge

Scan Length (µm) Scan Length (µm)

Arr

ay H

eigh

t (Å

)

Superfill Conventional fill

0.5µm/0.5µm Array 5µm/5µm Array

Sharp Transition

4.5µm/0.5µm Array

1.5µm/3.5µm Array

Array to ArrayTransition


Semi-Empirical Model for Topography Variation■ Physically Motivated Model Variables:

❏ Width, Space, 1/Width, and Width*Space

■ Semi-Empirical Model Development❏ Capture both conformal regime and superfill regime in one model frame

❏ 1/W2 and W2 terms explored as well

■ Model Form❏ Array Height:

❏ Step Height:

AH aEW bEW 1– cEW 2– dES eEW S× ConstE+ + + + +=

SH aSW bSW 1– cSW2 dSS e+S

W S× ConstS+ + + +=


Model Fit: Step Height and Array Height

10−1

100

101

102

−6000

−4000

−2000

0

2000

10−1

100

101

102

−6000

−4000

−2000

0

2000

Line Width (µm)

ArrayLine

IsolatedLine

Step

Hei

ght (

Å)

Step Height vs. Line Width

* = Datao = Model Fit

10−1

100

101

102

−4000

−2000

0

2000

4000

6000

Line Width (µm)

Env

elop

e H

eigh

t (Å

)

Array Height vs. Line Width

* = Datao = Model Fit

■ The models capture both trends well❏ Step Height RMS error = 327 Å❏ Array Height RMS error = 424 Å

■ Model coefficients are calibrated and used for chip-scale simulations


Chip-Scale Simulation Calibration Results

■ Simulated over the entire test mask used to calibrate the model■ RMS errors are slightly greater (about 90Å and 10Å more) than fitting RMS

errors since distribution values are used

1

1.2

1.4

1.6

1.8

2

2.2

x 104Final Thickness Average: Simulated Result

50 100 150 200 250 300 350 400 450 500

50

100

150

200

250

300

350

400

450

500

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Step Height Average: Simulated Result

50 100 150 200 250 300 350 400 450 500

50

100

150

200

250

300

350

400

450

500

−4000

−2000

0

2000

4000

6000

Envelope Average: Simulated Result

50 100 150 200 250 300 350 400 450 500

50

100

150

200

250

300

350

400

450

500

Array

Step

Final

Test

Thickness

HeightMask

RMS Error=440Å

RMS Error=420Å

Height


Integration of Electroplating and CMP Models■ Integration is done by feeding forward the simulated result

from electroplating to copper CMP simulation

■ Electroplating Simulation:• Array Height• Step Height• Topography Pattern Density

Prediction of dishing and erosion

Calibrated Copper Pattern Dependent

CMP ModelChip-Scale Simulation

Layout ParameterExtraction

Product Chip

Oxide

CopperLayout

Surface Envelope

■ CMP model needs:❏ Surface “envelope”:

Array Height❏ Step Height❏ Topography Pattern

Density


Topography Pattern Density■ Topography density: as-plated surface topography pattern

density of raised features❏ Depends on plating characteristics❏ Important as an input for CMP pattern density model

Topography DensityLayout Density

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1Grid Density: Layout Extracted

50 100 150 200 250 300 350 400 450 500

100

200

300

400

500

600

700

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1ECD Density: Simulated Result

50 100 150 200 250 300 350 400 450 500

100

200

300

400

500

600

700


Plating/CMP: Final Dishing

−400

−200

0

200

400

600

800

1000

1200

Dishing after step 3 polish

50 100 150 200 250 300 350 400 450 500

100

200

300

400

500

600

700

Dishing after step three

RMS Error = 140 Å

Å

0 5 10 15 20 25 30 35 40 45−220

−200

−180

−160

−140

−120

−100

−80

−60

−40

−20

0

20

Site number

Dis

hin

g (

A)

Data Model

Site number

Dis

hing

(Å)


Plating CMP: Final Erosion

1000

1500

2000

2500

3000

3500

4000

4500

Erosion after step 3 polish

50 100 150 200 250 300 350 400 450 500

100

200

300

400

500

600

700

Erosion after step three

RMS Error = 420 Å

Å

0 5 10 15 20 25 30 35 40 451400

1600

1800

2000

2200

2400

2600

2800

3000

3200

Site number

Ero

sio

n (

A)

Data Model

Site number

Ero

sion

(Å)


Conclusion■ Electroplating and CMP are Highly Pattern Dependent

■ Copper Interconnect Pattern Dependent Characterization❏ Test Structure Design

• Capture Key Pattern Effects: Isolated vs. Array, Density, Pitch, etc.• Three Polishing Length Scales: mm, 100µm, and 1µm Ranges.

❏ Mask Design• Single layer• Multi layer

❏ Physical and Electrical Measurements❏ Data Analysis

■ Can Be Applied to Support Process Development, Optimization, and Formulation Of Design Rules

■ Provides Data for Chip-Scale Modeling of Copper Interconnect


Acknowledgments■ Past and current students: Tae Park, Tamba Tugbawa, Brian

Lee, Xiaolin Xie, Hong Cai

■ Support and collaboration with SEMATECH, Texas Instruments, Conexant, Praesagus, SKW, Philips Analytical

pattern dependent characterization of copper interconnect

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