Metrology RoadmapMetrology Roadmap2000 Update2000 Update

EuropeEurope Alec Reader (Philips)Alec Reader (Philips)Wilfried Vandervorst (IMEC)Wilfried Vandervorst (IMEC)

Rudolf Laubmeier (Infineon)Rudolf Laubmeier (Infineon)

JapanJapan Fumio Mizuno (Hitachi)Fumio Mizuno (Hitachi)KoreaKorea

Taiwan Taiwan Henry Ma (EPISIL)Henry Ma (EPISIL)

USUS Bob Scace (NIST)Bob Scace (NIST)Alain Diebold (Int. SEMATECH)Alain Diebold (Int. SEMATECH)

AGENDAAGENDA

• 1999 ITRS

• 2000 Review (Why RED?)

• Requirements Tables for 2000 & 2001

1999 Metrology Roadmap Highlights1999 Metrology Roadmap HighlightsYear of First Product

ShipmentTechnology Generation

1999180 nm

2000 20012002

130 nm2003 2004

2003100 nm

Driver

DRAM 1/2 Pitch 180 165 150 130 120 110 100 D½Logic Isolated Lines 140 120 100 85 80 70 65 M Gate

Microscopy and LithographyMicroscopy resolution(nm) for P/T=0.1 1.4 1.2 1.0 0.85 0.8 0.7 0.65 MPU

Wafer Gate CDControl*

13 12 10 8.5 8 7 6.3 MPU

Wafer CD ToolPrecision* P/T=.2Isolated Lines**

2.6 2.4 2.0 1.8 1.6 1.4 1.3 MPU

Mask Area MetrologyTool Precision P/T=.2

4.8 4.2 3.4 2.8 2.6 2.4 2.2 MPU

Front End ProcessesLogic Dielectric ThickPrecision 1 (nm) B 0.0025 0.0024 0.0021 0.0017 0.0016 0.0013 0.0012

MPUGate

2D Dopant ProfileSpatial Resolution (nm) 3 3 3 2 2 2 1.5

MPUGate

InterconnectBarrier layerThick (nm)process range (± 3)Precision 1 (nm)

2320%0.08

1920%0.06

1620%0.05

1320%0.04

1120%0.035

720%0.02

320%0.01

MPU

Why are CD Measurement Requirements RED?

• There is no universal metrology solution for all CD measurements.– e.g., Scatterometry meets Focus-Exposure precision

needs to (70 nm node?) for resist lines but not for contacts (yet).

• 3D info needed for undercut gate, contact, and other structures.

• Precision includes tool matching and near + long term measurement variation.

CD-SEM a Potential Solution CD-SEM a Potential Solution for for

Wafer and Mask / R&D + ProductionWafer and Mask / R&D + Production

From Sato and Mizuno, EIPBN 2000, Palm Springs, CA

Barriers and Solutions

• 193 & 157 nm Resist Damage» lower dose images

• Precision Improvements» new nano-tip source

• Depth of Focus» new SEM concept needed

• Ultimate Limit of CD-SEM» ~ 5 nm for etched poly Si Gate

High Resolution

High Depth of Field Low Beam Energy

PICK ANY TWOPICK ANY TWO

Many Thanks to David JoyMany Thanks to David Joy

High Voltage ~200 keV is limited to High Voltage ~200 keV is limited to 1 nm resolution for SE imaging1 nm resolution for SE imaging

Ultimate limit of CD-SEMUltimate limit of CD-SEM

20nm

TBW =

10 nm

CD

Gabor’s limit

5 nm

TBW =

CD

The limit of CD -SEM is based on Secondary

Electron resolution is

the range of secondary electrons in the materialMany Thanks to David JoyMany Thanks to David Joy

17

Offset from CD-SEM by Angle

-20

-10

0

10

20

30

40

50

60

84 85 86 87 88 89 90 91 92

Sidewall Angle

CD

Off

set

(Sca

tter

om

eter

- S

EM

) Dense Line OffsetIsolated Line Offset

Is this evidence for loss of Depth of Field ?

CC Baum and S Farrer

60 nm node130 / 90 nm node 40 nm node

Schottky Emitter

Anode

Final Aperature

Detector

Magnetic Lens

Electrostatic Lens

Specimen

Z

Ucol

UE

CD

-SE

M

Depth of Fieldvs

Resolution

Damage to 193 Resist

from e beam &

DoF

Structure

Coherent Electron Beam

illumination footprint

detector

detector

e holography

CD Potential Solutions for Mask and WaferCD Potential Solutions for Mask and Wafer

60 nm node130 / 90 nm node 40 nm node

Schottky Emitter

Anode

Final Aperature

Detector

Magnetic Lens

Electrostatic Lens

Specimen

Z

Ucol

UE

CD

-SE

M

Depth of Focusvs

Resolution

Damage to 193 Resist

from e beam &

DoF

Structure

Coherent Electron Beam

illumination footprint

detector

detector

e holography

“Boot Tip”

Line Scan

CD

-AF

M

Tip technology low throughput Tip Technology

scat

tero

met

ry

Metal Gates

0th order

Incident LaserBeam

contacts

CD Potential Solutions for Mask and WaferCD Potential Solutions for Mask and Wafer

Materials Characterization Enables Materials Characterization Enables Process and Metrology DevelopmentProcess and Metrology Development

High Angle - Annular Dark Field STEMHigh Angle - Annular Dark Field STEM

GaAs

EELS Spectrometer

Annular Detector

1.4Å

As Ga

1.3Å Scanning

Probe

Objective Lens

I Z 2

Z=31 Z=33

Electron Beam

Thin Foil Sample

Image Plane

diffracted beammisses annular detector

Enlarged view of Lattice Planes“on axis” to electron beam

scatter from atoms or atomic columns

HA-ADF & EELS

0

500

1000

1500

2000

520 530 540 550 560 570

Interface

7Å from interface

Inte

nsi

ty (a.

u.)

Energy (eV)

Oxynitride and High k Interfaces

Dave Muller - Lucent

1.1MeV deuteron

14N(d,) 12C reaction:

12C

HeCapture & decay

14N

NRATotal N in oxynitride

Reason for Red is Precision and Tool Matching

IR or UV for In-Line ?

Existingin-line

metrology

zro2 Optical Constants

Photon Energy (eV)1.0 2.0 3.0 4.0 5.0 6.0 7.0

Rea

l(D

iele

ctric

Con

stan

t),

1

Imag(D

ielectric Constant),

2

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0

1.0

2.0

3.0

4.0

12

ZrO2 Dielectric Function

60 nm node130 / 90 nm node 40 nm node

Gate Dielectric Metrology Potential SolutionsGate Dielectric Metrology Potential SolutionsEnable High k Development with Existing ToolEnable High k Development with Existing Tool

Interconnect Metrology SolutionsInterconnect Metrology SolutionsBarrier/Seed Cu FilmsBarrier/Seed Cu Films

ZY

X

Wafer Positioning Stage

Sample

Detector

Aperture

Lens

Probe Laser

Excitation Laser

Neutral Density (ND) Filters

Phase Masks (PM)

Lens

Lens

20x 90 mm Spot Size

~1-2 seconds/point (measurement + data analysis + stage motion)

Excitation LaserDiode-Pumped, Pulsed, Frequency-Doubled Nd:YAG microchip laser. 600 ps Pulse

AlGaAs Diode Laser

5 Potential Solutions 5 Potential Solutions all expected to meet precision requirementsall expected to meet precision requirements

some are extendable to patterned waferssome are extendable to patterned wafers

Objective lens

GenerationlaserProbe laser

Beam splitter

Visionsystem

Detector

Detail inwafer

Junction

Beam

Excess carriers

X-Ray Tube

Thin-Film Sample

Monochromator

Spatially ResolvingX-Ray Sensor

0.15 mm 1psec

Pulsed Laser(200 fsec; 90 MHz) 800nm

Servo delay

Lens

FrequencyDoubler

photocell

Wafer

WavelengthSelector

Acoustic ISTSPicosecond acoustics

X-ray reflectivityX-ray fluorescence

Non-contact resistivity

Metrology & New StructuresMetrology & New Structures

Gate Gate

Drain

SourceVertical Vertical

TransistorTransistor

CD is a Film CD is a Film ThicknessThickness

CourtesyCourtesyRafi KleimanRafi Kleiman

LucentLucent

2000 and 2001 Changes2000 and 2001 Changes

• Accelerated Timeline Brings RED closer………..

• Developments in some CD measurements push Red out further for some applications?

Metrology Challenges by 2000 ITRS NodeMetrology Challenges by 2000 ITRS NodeTiming BringsTiming Brings RED RED CloserCloser

Technology Node 180 nm 130 nm 90nm 60 nm 40 nm 30 nm DriverLithography MetrologyWafer Gate CD nm post-etch contol

12 8 6 4 3 2 MPU

Wafer CD Tool 3 Precision P/T=0.2 Isolated Lines

2.4 1.6 1.2 0.8 0.6 0.4 MPU

Overlay Control (nm) (mean +3 )

65 45 31 25 20 15 MPU

Overlay Metrology Precision (nm) P/T=0.1

6.5 4.5 3.1 2.5 2 1.5 MPU

Front End Processes MetrologyLogic Dielectric Thick Precision 3 (nm) 0.0075 0.006 0.004 0.0032 0.0024 0.002

MPU

Metrology for Ultra-Shallow Junctions at Channel Xj (nm)

50.4 32.4 23.6 16.4 11.6 8 MPU

Interconnect MetrologyBarrier layer thick (nm) process range (±3 ) Precision 1 (nm)

1720%0.08

1320%0.04

1020%0.03

720%0.02

520%0.016

420%0.013

MPU