AML- Technical Benefits 4 Sept 2012 Wafer Bonding Machines & Services

AML In-situ Aligner Wafer Bonders Wafer bonding capabilities:• • • • • • • • • These various techniques have different tolerances to particles, wafer flatness, surface topography…. Anodic Bonding Si-Glass Direct Bonding e.g. Si-Si Glass Frit Bonding Eutectic Bonding Thermo-compression Adhesive Bonding Aligned Embossing In-situ UV cure Temporary Bonding RAD activation for low T bonding In situ chamber alignment & bonding = more process flexibility & higher throughput Wafer Bonding Machines & Services

AML in-situ Bonding Platform In-situ ‘Radical’ Activation External Optics +/-1 post bond AUTO alignment IR & Visible also NIR No alignment shift between alignment & bonding Water cooled platens Platens have adjustable parallelism Unique Wafer edge clamping system – no contact on bond surface In-situ chemistry Spring pin for Direct bonding Large gap between wafers during pump down / heating 2.5kV (current limited) for Anodic Bonding Vacuum or Controlled Process Gas pressure up to 2 bar absolute Fast pump down Vacuum- Independently heated Upper and Lower Platens (Max 560 0C) align hot or cold...

AWB Platform Outline Spec:• Unique In-situ alignment system (X,Y,Z & θ) Up to 1 micron accuracy manual & Auto alignment Full automatic PC control & data acquisition, Application of High Voltage up to 2.5KV Self contained dry pumping system (Turbo & back pump) for vacuum up to 10-6 mBar. Forced nitrogen cooling. 2” to 8” wafers (Depending on model chosen) RAD Wafer activation for low T bonding Water cooling In-situ Chemistry! Remote interrogation –via Teamviewer http://www.teamviewer.com Optics: Visible, IR & NIR (for highly doped wafers & hot alignment) Trend in MEMS to use highly doped wafers...

nhfL WAFER BONDING MACHINES & BONDCENTRE SERVICES WITH UNIQUE IN-SITU ALIGNMENT Manual Load Fully automatic Robot Wafer Load Fully automatic

Wafer bonding has found many applications in field of MST, MEMS, III-V, ICs & Optical devices: • MEMS devices - Pressure Sensors, Accelerometers, Microfluidics Vacuum encapsulation (absolute pressure, IR detectors…) 1st Level Packaging to isolate package induced stresses. Wafer scale Packaging – MEMS & IC III-Vs e.g. high performance LEDs bonded reflector - heat sink Temporary bonds for handle wafers (interlayer & direct) Advanced bonded substrates e.g. Si on Glass (SOG), GaAs on Si… Layer transfer - Smart cut Front End Bonded Substrates Starting material Wafer Bonding Machines & Services FAB...

Difference between AML & EV/SUSS • AML – align & bond in 1 machine, 1 process chamber • EV/SUSS need 2 machines; align wafers in an aligner then transfer wafers via a jig to a bonder Wafer Bonding Machines & Services

Align & contact wafers cold or hot at bond OR Intermediate temperature (reduces expansion misalignment due to TCE difference e.g. Si-Sapphire Allows out gassing at T and then align without waiting to cool down Wafer Bonding Machines & Services Wafers can ONLY be aligned and contacted COLD Spacers ~100 microns thick

Able to hold two wafers at different Temperatures, can keeping 1 wafer at high T & keeping other e.g. CMOS wafer at <400C Getter activation Impossible to keep wafers at different T Outgassing other wafer before getter wafer is activated – increasing its life Spacers ~100 microns thick Wafer Bonding Machines & Services

Confirm alignment accuracy before committing to bond Observe bonding process in real time to help speed up process development Impossible optics & bonding in different machines! BLIND! Spacers ~100 microns thick Wafer Bonding Machines & Services

No wafer movement between alignment & bonding – guaranteed alignment accuracy No Jig! Esp when “soft flowing” interlayer is present e.g. adhesive or glass frit Remove spacers – wafers sometimes move - & you will not know! Spacers ~100 microns thick Wafer Bonding Machines & Services

No flags touching bond surfaces so no damage or flag removal issues – Edge grip Wafer Bonding Machines & Services Flags touching wafer surface Spacers ~100 microns thick

Simultaneous Alignment, Heating & fast Pumping Heating & Pumping only Pumping rate low due to trapped volumes Spacers ~100 microns thick Wafer Bonding Machines & Services

Best system for vacuum encapsulation – outgas with separated wafers - Frit Reliable & known process gas conditions at the wafer surface i.e. Pressure (P) reading representative of P between wafers Unknown conditions at wafer surface. Pressure between wafers could be decades higher than measured in chamber Spacers ~100 microns thick Wafer Bonding Machines & Services

Spacing allows in-situ processing or Chemistry Impossible wafers in contact Spacers ~100 microns thick Spacing up to 30mm Wafer Bonding Machines & Services

Unique In-situ Chemistry CAB • Only machine to perform in-situ Chemistry, Align, Activate & Bond in 1 chamber without any handling between steps. Simple as CAB • e.g. Metal Oxide removal on the wafers surfaces just before alignment & contact – with forming gas or Formic acid - due to wide wafer separation in bond chamber • See paper Tyndall/UCL/AML ‘Waferbond’ conference, Chemnitz, Germany 6-8 Dec 2011 Many other possibilities; e.g. Plasma etch Oxide before wafer contact Wafer Bonding Machines & Services Vacuum or Controlled Process Gas pressure up to 2 bar III-Vs

Summary of AML Uniqueness & Benefits • Only machine that can align, activate & bond in 1 chamber without wafer handling • Only machine with high accuracy alignment adhesive bonding - with in-situ UV cure in vacuum Vacuum or Controlled Process Gas pressure up to 2 bar absolute • Ultimate Process Flexibility– Including Nano-Imprint – polymer embossing • Unique In-situ Chemistry Wafer Bonding Machines & Services