3D Interconnect for MEMS Devices

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(No Transcript)
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3D Interconnect for MEMS Devices
Collin Twanow Nancy Fares RD Manager On
behalf of President and CEO
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About Micralyne

• Pure Play MEMS foundry
• One-stop for Development and Manufacturing
• Experts in complex 3D MEMS

Contact info_at_micralyne.com 780 431
4400 www.micralyne.com
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MEMS What is it?

• MEMS Micro-Electro-Mechanical System
• Essentially a devices that interact with its
  surrounding environment or perform a mechanical
  function at the micron scale
• Think human sensors / structures
• Can be built with a IC toolset with the addition
  of a few specialty tools
• A MEMS device is either a
• Sensor, or
• Actuator, or
• Mechanical structure

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End Applications and Markets

• Consumer
• Off the shelf programmable components for
  designers. Accelerometers, Gyroscopes, reflector
  arrays for Display.
• iPhone orientation sensor, Wii mote sensor, DLP
  projectors
• Defense and Aerospace
• Self-sustained high precision IMU integrated into
  equipmentDisposable and extremely accurate
• Industrial/Structural
• Self-sustained sensors for strain or seismic
  sensing on buildings, bridges, etc.
• Life Sciences
• Implantable drug devicesSmaller, less intrusive
  healthcare

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MEMS Example
Airbag Accelerometer
Digital Light Processing TM Technology
Courtesy Texas Instruments
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Micralyne MEMS Example NASA LCROSS
NASA mission to determine if water existed at the
southern pole of the moon. Crash a rocket stage
into a crater, followed by a vehicle sensing
material from the ejection plume. Micralyne
provided MEMS processing on the detection element
of the NIR spectrometer that detected 5.6 water
in the crater. (Oct. 2009)
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MEMS Compared to ICs

• Similarities
• Wafer fabrication with common materials and
  fabrication methods
• Silicon wafers, dielectrics, metals
• Thin film deposition, photolithography
• Market desires increased functionality, reduced
  size and cost
• Differences
• Packaging considerations
• Fragile mechanical structures
• Many MEMS must have access to the surrounding
  environment
• Micron level minimum critical dimensions for
  mechanical structures
• Many device types, fabrication methods, and
  unique packages

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3D Integration the Fusion Era

• We are at the doorstep of the largest shift in
  the semiconductor industry ever, one that will
  dwarf the PC and even the consumer electronics
  eras.
• The core element needed to usher in the new age
  will be a complex integration of different types
  of devices such as memory, logic, sensor,
  processor and software, together with new
  materials, and advanced die stack technologies,
  all based on 3D silicon technology.
• Dr. Chang-Gyu Hwang
• Former President and CEO
• Samsung Semiconductor
• IEDM Conf., Dec. 2006

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3D IC MEMS integration
MEMS
MEMS
MEMS

• Smart Cores
• Dedicated information processing
• Each Smart Core will process information on its
  own
• Richer data collection
• Extended capabilities
• Reduce performance requirements across the system
• Lower power requirements with specialized
  processors
• Self-sustaining Smart sensors
• Upgrades are Plug and play
• Custom, scalable solutions
• Combined and sold as a complete system solution

MEMS Thermal Imager
MEMS
CPU
MEMS microphone
NIR Spectrometer
RF MEMS
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3D IC a threat? .
Not at all
Complimentary Goals
Similar challenges
P. Leduc CEA Leti 2007
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Technology Challenges in 3D Stacking

• Via Technology
• Via material
• Cu, W, or poly-Si
• Via process flow
• via first, via mid-process, or via last
• Bonding Technology
• Component arrangement
• wafer-to-wafer, wafer-to-chip, or chip-to-chip
• Bond-type
• Direct bonding, metallic bonding (Cu, CuSn, Au,
  AuSn), or glue bonding
• Bond alignment scheme
• face-to-face or face-to-back

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Via Materials
Cu Via
Poly-Si Via
P. Morrow et al., Intel, AMC 2004

• Why poly-Si?
• Good for high T processing
• Good for high voltage, low current applications
• Process compatabiliity

• Why Cu?
• Conductivity
• Compatibility with existing metals

M. Scannell, CEA-LETI 2007
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Via Process Flow
Via First
Via Mid-Process
Via Last
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Bonding Component Arrangement

• Why Chip-to-chip?
• Improved final device yields
• i.e. bonding wafers with random defect densities
  leads to lower device yield
• Incompatible wafer sizes
• i.e. 12 IC, 6-8 MEMS, 4 InP

• Why Wafer-to-wafer?
• Scalability
• Throughput
• Low Cost

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Key requirements for ICs

• Interconnect reduction
• RC delay, Power consumption, Cross talk
• Reduce Form Factor

• Shielding for Cross talk
• Conductive Via
• Cu, W, Poly-Si

P. Leduc CEA Leti 2007
Bonding of devices Multiple stack
bonding Compatibility of devices

• Cost reduction compared to SoC
• Enable new functionalities

• Higher Fault resistance
• Redundancy

Via Density
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Addressing the Challenges

• Integration of bonding and via technologies is a
  highly constrained problem ? many aspects of one
  couple with the other
• To break these constraints the focus should be
  upon
• Standardization across industry where appropriate
• i.e. a common Cu-Cu process for one bond in the
  total integration process is good. Using
  it for all the bonds necessary to integrate the
  desired device is bad (last bond ruins all
  the previous ones)
• Limiting the impact that the process technology
  associated with any one device functionality has
  on the overall complexity of the 3D integration
• i.e. if MEMS can produce a device that doesnt
  constrain the overall thermal budget at
  all, then that eases the other device constraints

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How do MEMS fit?
Set boundaries

• Define devices functionality
• Understand IC requirements for each
• Power, footprint, via density, delay

Revise MEMS process around IC requirements and
functionality

• Via Specifications
• Conductivity, material, dimension,
  density
• 2. Cross talk shielding and requirements

• Via specification will define thermal budget and
  bonding options

• Bonding options during MEMS process
• Bonding options for integration.

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Next Generation MEMS at Micralyne

• Micralyne Silicon Platform
• Bulk Micromachined
• Multi layered device
• Wafer level packaging
• Smaller footprint
• Through-Silicon-Via
• Integration (MEMS, IC)
• Allow room in the packaging / stacking thermal
  budget for IC integration

Cap Wafer
TSV
Device Layer
Base Wafer
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3D IC a springboard for MEMS?..
Absolutely

• Standardization
• Packaging, Integration
• With 3D IC
• Custom solutions
• Smaller devices
• Lower cost
• Drives innovation in the MEMS Industry
• Allows both MEMS and IC companies to focus on
  core competencies
• Device integration without additional design.
  Ie.) MEMS devices can use off the shelf analog
  components.

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Summary

• 3D IC is not a threat its an opportunity for
  further integration
• Major challenges ahead
• TSV
• Bonding
• Standardization
• 3D IC and MEMS Integration is the future
• Smaller, smarter, feature rich devices
• Sell solutions not components
• Through integration of software, IC, and MEMS
  significant amount of value can be generated
• Level of integration driven by performance, size,
  and cost trade-offs