1000 µm
10 µm

HEIDELBERG INSTRUMENTS
The Power of Direct-Write Lithography2022-03-11

3/9/22

Heidelberg Instruments Company Guide

2

Heidelberg Instruments in a Nutshell§ World leader in the development and production ofhigh-precision micro- and nanolithography systems

Laser§ Extensive know-how in developing customized
lithography solutions§ More than 250 employees worldwide§ 50 million Euros turnover in 2020
§ Founded in 1984
§ More than 1000 systems in more than 50 countries

Design data
Spatial Light
Modulator

Focussing lens

Substrate

ExposePhotoresist
SubstrateDevelopEtch

Stripresist

Changesin designHeidelberg Instruments Company Guide

3/9/22

Heidelberg Instruments Worldwide

Würzburg

USAUSA

Heidelberg
ZurichWürzburg

Heidelberg

As of January 2020JapanKorea
TaiwanChina

Installed Systems
Office Locations

3

Heidelberg Instruments Company Guide

Heidelberg Instruments Product Portfolio

3/9/22

4

Heidelberg Instruments Product Lines Overview
DWL

VPG+/ULTRADWL 66+

VPG+ 200/ 400/
800 /1100 /1400

DWL 2000GS/ 4000GS/8000GS

ULTRA

MPO

MLA

µMLA

NanoFrazor

MLA150

MLA300

NanoFrazor Scholar

MPO100

NanoFrazor ExploreDWL 2000/4000/8000GS
The High Resolution Pattern Generators
for Grayscale Lithography

DWL 66+
Ultimate Lithography
Research Tool

Our systems for direct
writing and low
volume mask making –the DWL series

Acousto-optic modulator and deflector
AOM0. order

Acousto-opticdeflector
AODscanφ

1. ordersin j =
RF-Voltage
f [MHz]RF-Voltage
f [MHz]t [µs]

Acousto-optic modulatort [µs]

l2d=l

f2cs

Exposure strategy: The raster scan

Advantages:• Design independent
write time
• High position accuracy•Structure fidelity

Exposure strategy: The raster scanyStage Positionx

ULTRA
Semiconductor Laser
Mask Writer

VPG+Small Area
Volume Pattern Generators

Large Area
Volume PatternGenerators

Model Number: F1088-HS
x The new F1088-HS has an enhanced modulearchitecture that supports column rates up to 350
kHz in AMP mode (1024 amplitude levels for eachpixels). Higher column rates can be achieved when
downloading a subset of pixels.
x The GLV module is separated from the control
electronics with a flex cable to allow smaller opticalhead designs and facilitates optical alignment.
x Available in UV, Visible, Violet, or IR versions.

The Grating Light Valve1088 Channel High-Speed GLV Module Specifications
NominalMaximum

Number of Pixels

Minimum

1080

1088

Pixel Pitch

25.5µm355nm

UV version

405nm

Violet version

Operating WavelengthNotes

450543658nm

Visible version

800

808

825nm

IR version

80

W

IR version

Laser Power
Optical Rise Time

500

nsec

0th-order operation

Optical Fall Time

700

nsec

0th-order operation

Image Data Resolution

10bitsColumn Rate
March 4, 2016

>6000 ribbons
1088 pixel

Unit

350

KHz

Ŷ Silicon Light Machines, 820 Kifer Road, Sunnyvale, CA 94086

Full 10-bit operationŶ

www.siliconlight.com

GLV: The Grating Light Valve:
A 1D-spatial light modulator:
Ribbons of silicon-nitride on silicon chip; upand-down-position changed by voltage
à Groups of ribbons form a diffractive gratingà 3 variable and 3 fixed ribbons per pixelà Modulating laser light as per design data

Exposure strategy VPG+:
Raster scan, continuous scrollingLaserlightsource

Designdata
Spatial Light
Modulator - GLV

MirrorFocusing lens
Scan width

Design andoperating
softwareScan direction
Writing
ProcessStage motion

Exposure strategy VPG+:
Raster scan,continuous scrolling
yStage PositionxμMLAMLA150
MLA300

Maskless Aligners

Exposure strategy MLA series

Bidirectional writingprocessSPEED

The DMDTM

Exposure strategy MLA series

The DMDTMDMD™ = digital multimirror device• MEMS device• Each pixel consists of an••••aluminum micromirror
Two bias electrodes tilt
the mirror either to+10°or -10°
ON (+10°): Mirror
reflects light into lens,pixel is brightOFF (-10°): No
reflection, pixel is dark
DMD contains more than442,000 micromirrors

-10°

+10°

Simplified representation of two tiltedmirrors (i.e. two pixels) in a Texas
Instruments DMD™
Schematic adapted from Marc J. Madou, Fundamentals ofMicrofabrication and Nanotechnology, Volume II, © CRCPress 2012

MPO100
Two Photon Polymertization

19

Core Technology | Two-Photon Polymerization (TPP)•

Two-Photon Polymerization (TPP) is a Direct Laser
Writing (DLW) technology. With TPP, the lightmatter interaction only takes place within thevolume of a focused laser spot.

•The simultaneous absorption of two photons in thefocused spot triggers the locally confinedpolymerization of an exposed photoresist.

•The laser focus can be moved through the volumeof the photoresist along all three spatial
dimensions. Complex 3D structures are written
along the laser’s trajectory, using light like a brush.

•Thanks to its versatility, TPP fabrication has
applications in many fields, including micro-optics,
photonics, micro-mechanics and biomedicine.

Laser beam

Air orimmersion
objective
Intensity

With or without cover glass
Voxel
Negative
photoresist
Substrate

Threshold

Simplified illustration of the Two-Photon Polymerization (TPP) process.

3/9/2220

MPO TPP Fabrication Process | Unparalleled design freedom
Nano – Micro – Meso – Macro
Multiphoton Optics’technology removes
limitations in designand enables the creationof free-form 3D
structures on virtually
any substrate including
active devices.

Features sizes can be as
tiny as 0.1 µm

Objects can be muchcloser than 1 µm

≥ 0.1 µm<< 1 µm

Achievable roughness can beadjusted as smooth as 5 nm

≤ 250 nmOverhangs do not
require supporting
structures

Extreme aspect ratiosof 16:1 and above
possible> 16:1
IFoV

Substrate can be chosen
independently≥ 5 nmadjustable

3/9/2221

Scale it. Shape it. | Focus on Functional Structures
MPO has developed and optimized processes to produce basic functional structures thatcan be integrated in a variety of components.

3/9/22

Microlenses/
microlens arrays

Prisms (2.5D)

DOEs/ diffusors

Free-form lensstacksWaveguides

Gratings

Meta structures

Filters/scaffolds

Microlens on
active device

Resonators

22

NanoFrazor

Heidelberg Instruments Nano
SwissLitho AG
9 March 2022

Technoparkstrasse 18005 Zurich, Switzerland

NanoFrazor Thermal Cantilevers
Key features» Ultra-sharp tip (silicon)» Integrated tip heater (resistive, up to 1100°C with 1 K resolution)» Integrated actuation (electrostatic for fast and accurate deflection)» Integrated topography sensor (unique AFM mode based on thermal distance sensor)
Tip with < 2 nm radius

5 µm
NanoFrazor Cantilever made of Si
Smart cantilever holder» Exchange within 1 min» Access almost any sample

2 µm

Glowing tip heaterPrinciple of NanoFrazor
Writing

Reading

Thermal probe

in-situ high-speed AFM» 10 nm sharp tip» fast and accuratedeflection» Inspection» Metrology» Overlay & Stitching

Laser sublimation

unique distance sensor» micrometerresolution» Level plane & Autofocus» 100x faster» Drift corrections» Other calibrations

Closed-Loop Lithography: Patterning & Imaging

1.
4.

2.

3.
Every few milliseconds:
1. Patterning one line with
hot tip
2. Cool down tip in few
microseconds
3. Image topography ofwritten line
4. Feedback algorithm toadapt patterning
5. Patterning of next line

» “What You See Is What You Get”
» No separate metrology necessary after
lithography» Check and online adaption of patterning
every few msÞDecrease total fabrication timeÞIncrease accuracy and reliability
www.heidelberg-instruments.com

Heidelberg Instruments Product Lines Overview
DWL

VPG+/ULTRADWL 66+

VPG+ 200/ 400/
800 /1100 /1400

DWL 2000GS/ 4000GS/8000GS

ULTRA

MPO

MLA

µMLA

NanoFrazor

MLA150

MLA300

NanoFrazor Scholar

MPO100

NanoFrazor Explore

Heidelberg Instruments Company Guide

3/9/2228

The Basic Principle•

Binary Exposure
LightExposure

Development

ResistSubstrate•

Gray scale Exposure
LightExposure

ResistSubstrate

Development

Exposure strategy in DWL systems
AOM(acousto-opticModulator)

U ~ Intensity
f ~ Deflection angle
AOD(acousto-opticdeflector)

MirrorFocusing lens
Scan width

Scan
Width

Substrate motion

Acousto-optic modulator and deflector
AOM
0. orderAcousto-opticdeflector
AODscanφ

1. ordersin j =
RF-Voltage
f [MHz]RF-Voltage
f [MHz]t [µs]

Acousto-optic modulatort [µs]

l2d=l

f2cs

Exposure strategy in DWL systems
AOM
RF-Voltage
U [V]

1. ordert [µs]

Pattern definition… in design coordinates(STL, XYZ-ASCII)… in bitmap grayvalues(BMP,PNG)… in design layers(DXF)(x1,y1,z1)
Layer 0Layer 1(x2,y2,z2)(x3,y3,z3)zyLayer nx

HIMT CONVERSION SOFTWARE
Coordinates(xi,yi)

Exposure DoseGV = {0,1024}

CAD data

Gray value data

Challenges in grayscale lithography...
Stitching & other defects

Resist non-linearity

Proximity & process effects

Design Layout

UV light distribution

Exposure ResultMaximum structure depth
Depth in resist [µm]0-10-20-30-40-50-60

Light intensity... and our solutions

Stitching optimization
Idea: Smoothen stitching by averaging multiple exposures

n-Over 4n-Over 10n-Over 40

CI-Over 4CI-Over 10

CI-Over 40“n-Over:“ n-times overlapping

1/2 stripe width -> “n-Over 2“Up to n-Over 40 possible

Depth in resist [µm]Intensity ( % of maximum energy)

Shape Optimization:Linearization

Gray value• Resist does not respond linearly• Minimum energy needed forphotoreaction• Exposure proximity effect• Lateral development effectGray value

Withoutli

nearization→ Geometry dependent37

GRAY SCALE OPTIMIZATION METHODS
Gray Value Table (GVT)

Automatic Intensity Correction(AIC)!

•••

Maps design gray value to customized grayvalue
Transformation at conversion level
Decrease of gray level resolution•••

Assigns design gray value to energy level
Transformation at exposure level
Keeps gray level resolution

Large Area Gray Scale Lithography

Depth in resist [µm]Intensity ( % of maximum energy)

Shape Optimization:Linearization

Gray value• Use of a non-linear
relation between GV
and energy:• One of 65000
energy levels
can beassigned toeach grayvalue

Gray value
AOMWi
thRF-Voltage
U [V]

255

12935255

17090
10135t [µs]linearization

Non-linearity & proximity effects
GVD approach
CHOOSE INITIAL GV
DISTRIBUTIONEXPOSURE

MODIFY GRAY VALUE

MEASURE GEOMETRY AND

DISTRIBUTION OR DESIGNCOMPARE TO TARGET

NO

YES

HeightOK?

FINAL EXPOSURE

XWhy we need 1024 Grey Levels
ABWhy we need 1024 Grey Levels

1024 levels

256 levels

B

A

D

256 levels

256 levels

CB

256 levels

DC

A

B

C

D！

Works quite well, but...
• ... can be very time consuming• ... requires compromises• ... fails for irregular designs

Target Cross
SectionNon-linearity & proximity effects
GVD approachHexagonal microlens array

Top view
Courtesy of IGI

Positions with same theoretical depth, butdifferent local environmentÞ Same dose assignment leads todifferent resulting depth!

Non-linearity & proximity effects
BEAMER 3D-PEC

Non-linearity & proximity effects BEAMER 3D-PEC
Example: DOE

46

THANK YOU! HEIDELBERG
INSTRUMENTS MIKROTECHNIK GMBH
MITTELGEWANNWEG 27
69123 HEIDELBERG
GERMANY PHONE +49 6221
728899-0
HEIDELBERG-INSTRUMENTS.COM