Smithers Pira the worldwide authority on the packaging, paper and print industry supply chains

Discover 3D

measurements for

flexible electronics: a

metrology masterclass

Samuel Lesko

Bruker Nano Surfaces

21 November 2013

Housekeeping

• Your moderator: Dan Rogers

Head of Digital Publishing

+Plastic Electronics

• Proceedings

• Questions & Answers

• Technical issues: use

chat feature

• Post event survey

Introducing Samuel Lesko

Samuel Lesko, Ph.D.

European Applications Manager,

Samuel.lesko@bruker-nano.com

• 13 years experience in

Applications at Bruker

• Earned Ph.D. in Burgundy

University (France).

Discover 3D measurements for flexible electronics: a metrology masterclass

Introductions Bruker Nano Surfaces Division

10/12/2015 5

• Scanning Probe Microscopy

• 3D Optical Microscopy

• Stylus Profilometry

• Tribology and Mechanical Testing

Introductions Bruker Stylus and Optical Metrology

10/12/2015 6

• Technology Leadership

• 60+ Patents

• 3 R&D 100 Awards

• 6 Photonics Circle of Excellence Awards

• Manufacturing Excellence

• Lean, six sigma-based process

• >100 systems/quarter capacity

• Rapid production ramp capability

Bruker NSD SOM is part of Bruker Materials (BMAT), a division of Bruker

What you will learn today

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• Be aware of 3D microscope techniques for metrology at nm, µm and mm scales

• How 3D microscopes based on light coherence help flexible electronic and PCB manufacturing

• Be able to decide with confidence whether this type of 3D microscope is right for your QC/QA needs

• Know the value delivered for accurate, gage capable imaging metrology by this core technology in flexible electronic and PCB

Outline

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• Technology review on 3D optical microscopy

• Principle of White light interferometry profiler

• Examples of imaging metrology applications

• Summary

9

L a t e r a l Feature Size

V

e

r

t

i

c

a

l

F

e

a

t

u

r

e

S

i

z

e

100 1 1 1 10 100 1 10 100 10 0.1

Å nanometers microns millimeters

1

1

10

100

1

10

100

1

10

100

0.1 Å

nm

µm

mm

CMM/

Surface

Contour AFM

Optical Profiler

Stylus

Profiler

Scatterometry

Surface profilometry: technology review

3D optical profiler based on WLI Z stack reconstruction by focal plan

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confocal interferometry

Low coherence of white light discriminates focal plan and

recording of Z stack allows 3D reconstruction of surface.

3D optical profiler based on WLI Always the best vertical resolution

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Repeatability over 8µm calibration step with 5x and 50x objectives

• Better than 0.1%

• Independent from Numerical Aperture of objectives

Vertical background noise < 3nm

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This technic has expanded toward:

• Amazing lateral resolution: up to 150 nm

• Rough samples: up to 65°slope with 5x objective

• Smooth steady slopes: 45°capability

3D optical profiler based on WLI Last evolutions

200nm grid / abrasive cone with 60° slope / Crystals with 40°slope

ContourGT and ContourSP Table top to high end automation

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ContourGT-K manual

ContourGT-I Table top automated

ContourGT-X Advanced automation with wafer loader capability

SP – flat panel , large substrate and PCB

Polymer substrates Roughness & waviness study

Slide 14

• Fine features and large waviness affects:

• Adhesion of deposited film

• Longevity of deposited film

• Requirements:

• Fast

• Large field of view

• Vertical resolution below 1nm

Mylar

Silicone

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Inkjet Applications Development

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• Inkjet enters new era:

• Custom OLED display as an OEM inkjet manufacturing

• RFID sensor growth

• New processes/ink/nozzles to refine lateral resolution

• OEMs supplying print devices in this space will need to verify that heads (fixed heads, disposable heads) are accurate and provide best quality volume control for end application

Volume Characterization on OLED Display Manufacture Application

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• Lateral & vertical resolution ensure proper metrology in tight GR&R requirement

• 0.25 pL volume dots, measured with world-leading accuracy and repeatability for ink nozzle output control

• 3 seconds per measurement with automated tilt/focus – allows high throughput for quality monitoring over long run

Brief Processing Overview Solar – Large substrate a-Si Thin Films

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Laser Scribe

Transparent Oxide Spray/Sputter/APCVD

Semi-Layer Dep. PECVD/PVD/Evap/Ink

Laser Scribe

Metalization Screen Print

Glass or Stainless

Au

tom

ate

d

Co

ntin

uo

us P

rocess

Laser Scribe

Veeco Instruments

Roll to Roll PVD Deposition

InnoLas Laser Scriber

Applied Materials PECVD

17

Solar panel Silver line study

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• Accurate, fast 3D surface texture

• isolation, trace uniformity

• Volume control

Ag paste/trace analysis

18

Solar panel Texture analysis across the roll

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19

Multiple inspection points enable easy correlation and computation of relative efficiency to master

19

Various texturing processes Optical 3D microscopy differentiates

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Alkaline etch - Sbi, Sdr, Sdq

Acid etch (Ssk)

20

Copper Wire Bonding Process Reliability issues

Aluminium splash on Cu bonding

SEM control: time consuming

& partial information

Splash

Splash

Depth

21 October 12, 2015

Copper Wire Bonding Process Optical profiler

22

Color image overlay

over 3D topography

Wire Bond Cavity,

Depth ~ 1 µm

Time to Data < 15s

Sample prep = 10 mins

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Why section is not enough? Need for 3D characterization

211% fluctuation

October 12, 2015

23

Optimisation of analysis Need for advanced functions

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Raw Data Remove Tilt Mask Non-Relevant

Area

Final Analysis

Copper wire bonding Full automatic analysis

Bruker Confidential Stylus and Optical Metrology Unit

Operator level interface One click analysis

10/12/2015 26

Printed Circuit Board HDI Development

10/12/2015 27

PCB key requirement Need longer working distance

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• First, some sample like the IC chip below requires working distance of > 1mm so that while measuring the die at the center, the objective will not crash at the molding compound.

• Secondly, it is more user friendly, operator will not crash the objective on the sample easily while focusing on the sample.

Z > 1 mm

PCB key requirements Throughput

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One Image Acquisition

SPEED = Image Acquisition + Data Analysis

Multiple Analyses Same

Speed !!!

HDI PCB and Substrate Applications

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Via Recess / Dimple Copper Trace

Via Via and pad

Alignment

Roughness, depth,

width on top & bottom

Conclusion

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• White light interferometry profiler enables

• Undisturbed measurement over flexible membrane

• High throughput & accuracy

• Single characterization tool for all applications

In the field of flexible electronic and PCB

• Contrary to other optical technic, it has intrinsic benefits of constant sub-nm vertical resolution:

• Safer operation

• PCB ready measurement

© Copyright Bruker Corporation. All rights reserved.

www.bruker.com

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