n&k Analyzersn&k Analyzers

TFUG -- Sept. 21, 2005

Comprehensive Metrology Tools forCharacterization and Measurements of

Ultra-Thick Films, Determination of Optical Properties of Materials

n&k Technology, Inc.Santa Clara, CA

OutlineOutline

TFUG -- Sept. 21, 2005

Introduction

n&k Technology, Inc.

Algorithm and Hardware Improvements

Examples of Ultra-thick Photoresists

Section I: IntroductionSection I: Introduction

TFUG -- Sept. 21, 2005

Wafer bumping packaging technology to pack chips more closely together

Bump bonding technique uses ultra-thick resists to define size and location of bonds

Resist thickness typically range in 50 to 100 µm, or more, substantially more than resists used in IC manufacturing

n&k Technology provides a solution to address the needs of Advanced Packaging industries

Section II: The CompanySection II: The Company

TFUG -- Sept. 21, 2005

The Company

Optical Systems

Products

Forouhi-Bloomer (FB) Dispersion

The Company: The Company: n&k Technology, Inc.n&k Technology, Inc.

TFUG -- Sept. 21, 2005

n&k Technology designs, manufactures, and sells systems, termed n&k Analyzers, for characterization of thin films, and measurements of optical properties and critical dimensions.

Founded in 1992 by Dr. Rahim Forouhi and Dr. Iris Bloomer.

Privately held.

August 1999 - Al Shugart International invested in n&k Technology.

n&k Technology’s roots originated in the 1980s with the discovery of the equations for n and k by the founders.

n&k Technology offers a broad product portfolio for production and R&D applications in:− Semiconductor industry (Si and GaAs)− Photomasks industry− Data storage market (magnetic, optical, and magneto-optical)− Flat panel displays − Optical coatings and filters

Currently, more than eighty (250) companies, operating in twelve (12) countries, use n&k Analyzers, multiple units.

Fully Automated n&k Analyzers for Wafer FabricationFully Automated n&k Analyzers for Wafer Fabrication~3300 Platform~

TFUG -- Sept. 21, 2005

n&k 3300 Bridge ToolFor 2" – 12" Wafers

n&k 3300For 12" (300mm)Wafers

•Semiconductor Wafer Processing Applications (Si, GaAs, InP, etc.) •Microspot Technology•Pattern recognition•Automated X-Y Mapping

•Automated Loading/Unloading•Automated Z-Direction Stage Movement•Supporting manual load port, SMIF, and FOUP

n&k Analyzer 1700n&k Analyzer 1700

TFUG -- Sept. 21, 2005

Overviewn&k 1700 Technology

• n&k Patented, all Reflective OpticsDUV-Visible-NIR, 190 nm - 1000 nm, 1 nm step

• Simultaneous Determination of n, k and thickness• Agilent Technologies Spectrophotometer Electronics• Cognex Machine Vision• 8" x 8" or 12" x 12" Automated Stage• n&k Technology Thin Film Data Analysis Software• n&k Technology Patented, Microspot Feature Analysis

Software

Application:• Ultra-High Resolution Thin Film Metrology on

Patterned Wafers• Micro-Feature Film Parameter Mapping

Optical System (Optical System (n&k Technologyn&k Technology))

TFUG -- Sept. 21, 2005

n&k Analyzersn&k Analyzers DifferentiatorDifferentiator

TFUG -- Sept. 21, 2005

Wavelength Range− The measured raw data should cover the entire deep UV

to near IR wavelength rangeSignal to Noise− The measured raw data should have a good signal to

noise ratio over the entire wavelength rangePhysical Model− A valid physical model should be used to analyze the

measured raw data

Dispersion EquationsDispersion Equations

TFUG -- Sept. 21, 2005

Forouhi-Bloomer:

Cauchy:

Harmonic-Oscillator:

k kk k

( )λλ λ

= + +012

24

ε ωω ω ω

ω ω γ ω12 2

202 2

02 2 2 2 21( )

( )( )

= − = +−

− +∑n k p

ii

i i

i

n nn n

( )λλ λ

= + +012

24

εγ ωω

ω ω γ ω2

2

02 2 2 2 22= =− +∑nk i p

ii

i

i

( )( )

k EA E E

E B E Ci g

i ii

q

( )( )

=−

− +∑2

2

∑ +−+

+∞=q

i ii

oioi

CEBECEBnEn 2)()(

ii--line Photoresistline Photoresist

TFUG -- Sept. 21, 2005

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900

Ref

lect

ance

Photoresist (i line) / Si-sub

Green line: Theoretical (from F-B)

Wavelength (nm)

Red line: Measured

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900R

efle

ctan

ce

Green line: Theoretical (from Cauchy)

Photoresist (i line) / Si-sub

Wavelength (nm)

Red line: Measured

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900

Ref

lect

ance

Green line: Theoretical (from Oscillator)

Red line: Measured

Photoresist (i line) / Si-sub

Wavelength (nm)

0.0

0.5

1.0

1.5

2.0

2.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts

n

k

Photoresist (i line)(F-B)

0.0

0.5

1.0

1.5

2.0

2.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts n

k

Photoresist (i line)(Cauchy)

0.0

0.5

1.0

1.5

2.0

2.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts n

k

Photoresist (i line)(Oscillator)

SiONSiON

TFUG -- Sept. 21, 2005

0.0

0.1

0.2

0.3

0.4

200 300 400 500 600 700 800 900

Ref

lect

ance

t = 297 A

Red line: Measured

SiON / Si-sub

Wavelength (nm)

Green line: Calculated (from F-B)

0.0

0.1

0.2

0.3

0.4

200 300 400 500 600 700 800 900R

efle

ctan

ce

t = 331 A

Red line: Measured

SiON / Si-sub

Wavelength (nm)

Green line: Calculated (from Oscillator)

0.0

0.1

0.2

0.3

0.4

200 300 400 500 600 700 800 900

Ref

lect

ance

t = 306 A

Red line: Measured

SiON / Si-sub

Green line: Calculated (from Cauchy)

Wavelength (nm)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

200 300 400 500 600 700 800 900

Wavelength (nm)

Opt

ical

Con

stan

ts n

k

SiON(F-B)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

200 300 400 500 600 700 800 900

Wavelength (nm)

Opt

ical

Con

stan

ts

n

k

SiON(Oscillator)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts n

k

SiON(Cauchy)

SiO2SiO2

TFUG -- Sept. 21, 2005

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900

Ref

lect

ance

t = 1066 A

Green line: Calculated (from F-B)

Red line: Measured

SiO2 / Si-sub

Wavelength (nm)

0.0

0.5

1.0

1.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts

n

k

SiO2(F-B)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900R

efle

ctan

ce t = 1073 A

Green line: Calculated (from Oscillator)

Red line: Measured

SiO2 / Si-sub

Wavelength (nm)

0.0

0.5

1.0

1.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts

n

k

SiO2(Oscillator)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

200 300 400 500 600 700 800 900

Ref

lect

ance t = 1066 A

Green line: Calculated (from Cauchy)

Red line: Measured

SiO2 / Si-sub

Wavelength (nm)

0.0

0.5

1.0

1.5

200 300 400 500 600 700 800 900Wavelength (nm)

Opt

ical

Con

stan

ts

n

k

SiO2(Cauchy)

TFUG -- Sept. 21, 2005

Section III: Improvements For Section III: Improvements For UltraUltra--thick Film Applicationsthick Film Applications

Typical Problem of Ultra-thick Film Analysis

Algorithm Improvements

Hardware Improvements

TFUG -- Sept. 21, 2005

Typical Problem of UltraTypical Problem of Ultra--thickthickFilm Analysis Film Analysis –– Multiple Local MinimaMultiple Local Minima

0

20

40

60

80

100

200 300 400 500 600 700 800 900

R &

T (%

)

Wavelength (nm)

R-exp R-cal

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

6000 8000 10000 12000 14000 16000 18000 20000

Thickness (A)

Erro

r Bet

wee

n Ex

perim

ent A

nd

Cal

cula

ted

Ref

lect

ance

(RM

S)

Wrong solution!

TFUG -- Sept. 21, 2005

A More Robust Way to EstimateA More Robust Way to EstimateA FilmA Film’’s Starting Thicknesss Starting Thickness

Phase ϕ = 2π/λ *∆= 2π/λ * (2*n*t*cosθ')

∝ n*t / λ

Number of fringes isproportional to n and t

0

20

40

60

80

100

200 300 400 500 600 700 800 900

R &

T (%

)

Wavelength (nm)

R-exp

20

40

60

80

100

1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

R &

T (%

)

eV

R-exp

iline resist in λ space iline resist in 1/λ space

Tests on Simulated SpectraTests on Simulated Spectra

TFUG -- Sept. 21, 2005

0

50

100

150

200

250

300

350

400

450

50 100 150 200 250 300 350 400 450

Simultated Resist Thickness (Microns)

Cal

cula

ted

Thic

knes

s (M

icro

ns) Method 1

Method 2

TFUG -- Sept. 21, 2005

Higher Resolution SpectrophotometerHigher Resolution SpectrophotometerReflectance of 300Reflectance of 300µµm Glass Slidem Glass Slide

5.5%

6.0%

6.5%

7.0%

7.5%

8.0%

8.5%

820 840 860 880 900 920 940 960 980 1000 1020

Wavelength (nm)

Ref

lect

ance

(%) Full Spectral

Range

5.5%

6.0%

6.5%

7.0%

7.5%

8.0%

8.5%

840 841 842 843 844 845

Wavelength (nm)

Ref

lect

ance

(%) Same Data,

Zoomed Range20x Improvement!

Section IV: UltraSection IV: Ultra--thick Film Applicationsthick Film Applications

TFUG -- Sept. 21, 2005

Correlation with Profilometry

70 and 100µm Photoresist Measurements

Repeatability and Reproducibility of Results

Applications: Ultra Thick FilmsApplications: Ultra Thick Films

TFUG -- Sept. 21, 2005

TFUG -- Sept. 21, 2005

Applications: Ultra Thick FilmsApplications: Ultra Thick FilmsCorrelation with Correlation with ProfilometryProfilometry

Example of 100 Example of 100 µµm Photoresist Spectram Photoresist Spectra

TFUG -- Sept. 21, 2005

Reflectance from 900 – 1000nm, 100um Resist

TFUG -- Sept. 21, 2005

Applications: Ultra Thick FilmsApplications: Ultra Thick FilmsRepeatability and Reproducibility StudiesRepeatability and Reproducibility Studies

ConclusionsConclusions

TFUG -- Sept. 21, 2005

Demonstrated ultra-thick resists capability provides manufacturers with a fast, accurate, repeatable, and non-destructive characterization tool for process monitoring.

No blindspots in the entire thickness range – due to innovative analysis algorithm.

Measured 300 µm film (eg, glass slide). High resolution detector allows comfortable measurement up to 600 µm, and more. Ultimate thickness not known – limited only by the quality of film.

Non-destructive, fast measurements – less than 3 seconds per site.

Excellent repeatability and reproducibility compared to traditional methods.