AML Equipment & Services overview

AML – Wafer Bonding Machines & Services

 Who is who in AML
(Main contacts)

Rob Santilli - Managing Director ( & Founder)

Tony Rogers - Technical Director ( & Founder)

David Adamson - Manufacturing ( & Founder)

Vince Wilson - Sales & Business Development

Manager

Nick Aitken - Applications Engineer

Sue Pepler - Administration

AML – Wafer Bonding Machines & Services

 AML- Company History

• Company founded 1992

• MEMS Design, Manufacture & Process Development background

• Founders made first in-situ aligner-wafer bonder in 1985

• AML focus on & Provide Wafer Bonding equipment & Wafer bonding
services (BONDCENTRE)

•Worldwide installed base of machines

From MEMS
background not Mask
Aligner for IC

AML – Wafer Bonding Machines & Services

 Basic features of AML bonders

AML – Wafer Bonding Machines & Services

Schematic of Unique in-situ Activation, Alignment &
Bond

T <560
C

HV
•Heat + Pump + Align
<2500V
•Independent platen T
•Flexible
•2 to 8 inch wafers
AML – Wafer Bonding Machines & Services
•Fast cycles times
 AML Wafer Bonders
Wafer bonding capabilities:-

• Anodic Bonding Si-Glass

• Direct Bonding e.g. Si-Si
• Glass Frit Bonding
• Eutectic Bonding
• Thermo-compression
• Adhesive Bonding
• Aligned Embossing

In bond chamber alignment

& bonding
in one machine
= higher throughput
AML – Wafer Bonding Machines & Services
 AML Advantages
One System Does it ALL (Align, Activate and Bond in one bond
chamber)

ALIGN / BOND
• No wafer movement between alignment & bonding – guaranteed
alignment accuracy
• Simultaneous alignment, heating and vac pump-down (fastest cycle
time)
• In-bond chamber alignment at bond temperature (reduces expansion
misalignment effects you would see with competitors jigging)
• No flags touching bond surfaces so no possibility of contamination,
damage or flag removal issues
• Best system for vacuum encapsulation (Large gap between wafers
during pump-down)
• Independent control of upper & Lower wafer temperatures –
(useful for getter activation)
• Best system for reducing / forming gas environment - e.g. for
eutectic bonding. (reproducible wafer surface environment)
• Wide range of processes possible – Including Nano-Imprint

AML – Wafer Bonding Machines & Services

 AML Advantages
ACTIVATE (enables low temperature Direct
Bonding)

• In-bond chamber RAD activation option –

activated surfaces cannot be re-contaminated

• Less surface roughening and more uniform

activation than plasma

• No exposure of wafers to energetic ions --> can

be used with sensitive device wafers

• Wider process time window for activation than

with plasma- process time less critical

• In-situ system provides better reproducibility and

therefore better process stability

AML – Wafer Bonding Machines & Services

 AML Advantages
ECONOMIC
• Lowest cost per bond & ownership

• No mask aligner required- free to choose best mask aligner for

your ‘mask aligning’

• System is complete – no other equipment required

• Reasonably priced spares

EASY
• Very high reliability – minimal servicing – fast & simple to maintain

• Standard machines as well as custom options to suit specific

customer needs

• Easy to use - system up and running and in use in minimum time

SUPPORT
• Excellent process support via BONDCENTRE – fast response

• More than 20 years machine & wafer bonding process experience.

• Worldwide Machine base.

AML – Wafer Bonding Machines & Services
 AML tooling solutions for Direct
Bonding

• Ideally Si-Si bond is self propagating- minimises

stress/bow in the resulting assembly
• The AML spring pin / edge clamp tool allows control
of self bond propagation rate and bond initiation point

AML – Wafer Bonding Machines & Services

 Bonding Tool
Wafer bow system

Variable force and

displacement

lower chuck

• The displacement and force exerted in

bowing the upper wafer is tuned with
respect to the stiffness of both wafers.
• The profile and force distribution of the
lower pin chuck can be tuned to give the
required profile in the bonded assembly –
flat or reduced stress.

AML – Wafer Bonding Machines & Services

 Example Bond

IR transmission image of
void free Si – Si direct
bond. 100mm wafers.
Bond performed on
AML402 direct bonder -
using pin chuck system

AML – Wafer Bonding Machines & Services

 New system features, now
and planned

AML – Wafer Bonding Machines & Services

 New Processes on AML Wafer Bonders
• Hot Embossing – Characterisation has just started

New Developments on AML Wafer Bonders

• Inclusion of RAD in-situ surface activation for low temperature
bonding (available for new orders) see page after next
• Addition of Pattern recognition software
• Inter-pixel measurement for sub-micron alignment accuracy
• Upgrading of manipulators from manual to stepper motor control
• Motorised Z Drive
Development pipeline:- System Automation

AML – Wafer Bonding Machines & Services

 New Polymer Micro Hot Embossing
& Nano Print tool

• Applications: e.g. Bio-sensors &

Microfluidic devices
• Polymers: SU8, PDMS, PMMA..
• Tool fits AML bonder platform or
stand alone machine

Outline Specification
Force up to 5000N Stroke up to 750 microns
T up to 500 C (cooling) up to 6” wafers
2 micron alignment between
Operation in Vacuum
stamp & substrate

AML – Wafer Bonding Machines & Services

 Basic Bonding Methods
offered:
• Anodic
• Direct (Fusion)
• Low Temperature (activated) Direct
• Thermocompression
• Eutectic
• Glass Frit
• Adhesive

AML – Wafer Bonding Machines & Services

AML AWB04 Aligner Bonder

AML – Wafer Bonding Machines & Services

 Anodic Bonding
• Graphite upper platen (reduced voids and no back surface
stains)

• Current limited bonding (enables bonding to thick

insulating layers and reduces stress variation across the
bonded wafers, and reduces risk of electrical breakdown)

• Aligned triple stack (sequential & Simultaneous process)

AML – Wafer Bonding Machines & Services

 Direct Bonding
• In-situ Radical activation enables unique
“Activate, align & bond” capability

• In-situ activation provides controlled

environment for process development
and bond interface reproducibility

• In-situ activation also enables removal of

hydrocarbon contamination

AML – Wafer Bonding Machines & Services

Schematic of Unique in-situ Activation, Alignment &
Bond

T <560
C

HV
•Heat + Pump + Align
<2500V
•Independent platen T
•Flexible
•2 to 8 inch wafers
AML – Wafer Bonding Machines & Services
•Fast cycles times
 Radical Activation Tool

Experimental set-up using glass vacuum chamber – showing

electrical discharge confined between the ring electrodes

AML – Wafer Bonding Machines & Services

 IR transmission Image
150mm RAD activated
bond

Void free in situ activated bond

– annealed at 200C for 1 hr

AML – Wafer Bonding Machines & Services

 Radical-Co-axial Source
Gas supply

Only Earthed screen

radicals
in this
region
Source

Source
DC source

Wafers
for in-situ
activation

R. pump

AML – Wafer Bonding Machines & Services

 Radical Activation Tool
Measurement show that there is no plasma
in the centre zone. All that remains that could affect
the wafers surfaces is radicals and UV radiation

Electron Density (discharge ring) ≈ 2.5 x 10 16 m-3

Electron Density less than 5 x 10 13 m-3 in

the centre (wafer activation region)

Ion flux very low in the centre

AML – Wafer Bonding Machines & Services

 Radical Activation
XPS spectra showing comparison of silicon wafer
before and after activation by Oxygen Radicals
Spectra of untreated and treated silicon Spectra of untreated and treated silicon

Untreated Centre

6000 6000

5000 5000

4000 4000
Counts per second

Counts per second

3000 3000

2000 2000

1000 1000

0 0
1000 800 600 400 200 0 1000 800 600 400 200 0
Binding energy /eV Binding energy /eV

Shows reduced carbon peak post exposure

AML – Wafer Bonding Machines & Services

 Some Radical Activation Results
3.00
radicals
2.50
O2 plasma
-2
Bond strength /J.m

2.00

1.50

1.00

0.50

0.00
0.000 5.000 10.000 15.000 20.000 25.000
Exposure Time /min

Comparison of Radical vs Plasma Activation Bond Strength for

Various Activation Exposure Times (strength measured using
Razor Blade Method)
AML – Wafer Bonding Machines & Services
 Some Radical Activation Benefits
Produces less roughening of the surface than plasma activation
Uniform activation (no edge effects as typically seen for plasmas)
Wider process time window for activation
In situ process eliminates variation in activation strength with time
No exposure of wafers to energetic ions
Bond can be heated / contacted at bonding temperature = significant
advantage for dis-similar substrates or “hard to bond” substrates

AML – Wafer Bonding Machines & Services

 Uniform Force Bonding
Uniform force is needed for the following bonding processes

Glass Frit
Eutectic
Thermocompression
Adhesive

Platen / support structure designed to give uniform force across

the platen area
Use of graphite inserts further improves the force uniformity

AML – Wafer Bonding Machines & Services

 Improvements in Force Uniformity
Old Bonders New Bonders

The above images were obtained using pressure sensitive film. The
black areas are full scale, white areas are zero load.

AML – Wafer Bonding Machines & Services

 Some Customer References
Customer Details
Laboratory for Electro-Optics Systems (LEOS)
Bangalore, India
Louisiana State University
Baton Rouge, USA
Sumitomo Precision Products Co. Ltd.
Japan
Fraunhofer Institute
IZM Berlin, Germany
Korea Photonics Technology Institute (KOPTI)
Guangju, Korea
CNRS-LAAS
France
Xiamen University
China
Fraunhofer Institute
Halle, Germany
Semefab Ltd
UK
Tyndall Institute
Cork, Ireland

AML – Wafer Bonding Machines & Services

 BONDCENTRE

Wafer Bonding Services

AML – Wafer Bonding Machines & Services

 Why BONDCENTRE?
• There is a business in bonding wafers for people!
• The penetration of Wafer Bonding into many new areas
outside MEMS, warrants special attention & resources to
satisfy the wide range of bonding process requirements.
Good opportunity!
• The more processes that are developed the more reasons
there are to buy AML machines.
• Niche – no one else is doing this!

AML – Wafer Bonding Machines & Services

 Strengths

• Very strong MEMS design & process background –

especially with respect to Wafer Bonding
• Relevant customer base
• Strong network of partners built up over many years
• Equipment supplier – transfer the process onto a machine
• Selected by UK government to be best to provide the
service

AML – Wafer Bonding Machines & Services

 BONDCENTRE SERVICES OFFERED

• Wafer Bonding Process Development e.g. for many novel materials;

silicon, glass, sapphire, strained silicon, InP, GaAs,…
• Wafer Bonding process selection & design for your application
• Commercial Wafer Bonding Service prototype to production
• Wafer Bonding Technology Transfer (inc Equipment) & Training
• Associated Processes (Pre & Post Bond)
• Applications knowledge for:
MEMS Smart cut layer transfer
Advanced Substrates Wafer Level Packaging
3D integration Vacuum Encapsulation
Temporary Bonding LEDs

AML – Wafer Bonding Machines & Services

 Associated Pre & Post Bond Services:

• Wafer Cleaning & Activation

• Wafer Characterisation e.g. Profiling & Surface
Roughness
• Wafer Structuring: e.g. Channels, Holes &
Conducting Vias
• Wafer Processing: e.g. Deposition, Electroplating
• Wafer Preparation: Thin to required Thickness &
Surface Finish - Planarisation (CMP)
• Inspection of bonded assemblies - SAM & IR

AML – Wafer Bonding Machines & Services

 Equipment Set Available:
• WAFER ALIGNER BONDERS 4 machines in Class 10
• METROLOGY; AFM, Ra, PROFILE, TTV
• MEGASONIC WAFER CLEANING
• NEW ‘RAD’ ACTIVATION
• INSPECTION: ACOUSTIC MICROSCOPE (SAM) & IR
• ELECTROPLATING
• SCREEN PRINT - GLASS FRIT/ADHESIVE
• POWDER BLASTING E.G. GLASS MACHINING
• WAFER THINNING
• CMP

• Also access via long term collaboration with CMF @ Rutherford to:
• PHOTOLITHOGRAPHY DEPOSITION- PVD & CVD & FURNACES
• ETCHING – DRY & WET
• WAFER SAW WIRE & BUMP BONDING
• METROLOGY: THIN FILM, LINE WIDTH, SEM
AML – Wafer Bonding Machines & Services
4 Aligner –Bonders in class 10

AML – Wafer Bonding Machines & Services

SAM – Scanning Acoustic Microscope

AML – Wafer Bonding Machines & Services

 Many thanks!

AML – Wafer Bonding Machines & Services