Prof. Rao R. Tummala in ECE

1
Greetings from Georgia Tech PRCChanging Role
of Packaging From ICs 3D ICs 3D Systems

• Prof. Rao R. Tummala in ECE MSE
• Pettit Chair Professor Director
• Microsystems Packaging Research Center
• Georgia Tech.,USA

2
3D ICs to 3D Systems

• The impact of 3D ICs is profound
• But systems are more than stacked ICs
• We need leading-edge ICs,3D ICs and 3D systems
  technologies for leading-edge products
• New technologies take more than 10 years to
  develop

3
Executive Summary

• Packaging means System Integration
• Two components to systems devices non-devices
  (system components) device Packaging system
  packaging)
• Miniaturization is the most important single
  parameter in electronics
• Miniaturized IC to 45nm. Beyond 22nm in CMOS
  uncertain.
• Miniaturization began with 3D IC stacking, as
  the potential solution to ICs beyond 22nm.
• But 3D ICs are a small part of any system
• 3D- system is the final holy grail
• As we miniaturize the system to Nanoscale, can it
  lead to a single technology platform? This is
  the basis of 3D ASSM

4
Why Miniaturize?

• Miniaturization leads to
• Lower Cost
• Higher Performance
• Higher Reliability
• Higher Functionality
• Examples
• ICS from 1 micron to 32 nm
• WB to FC to TSV
• Ceramic to Organic
• PTH to SMT

5
Systems Trends
6
System Trends Moving toward All-in-one Product
Additional Functions in Handset
/Digital Convergence
Independent Market
All-in-one Products
2G
3G
2.5G
?
2004 2007
2002 2003
2001
ea
ea
ea
Source Samsung Electronics
7
Miniaturization of Systems Trend
Laptop
SINGLE FUNCTION
Functional Density or Component Density / cm3)
Cellular
SMART Watch Bio-sensor
MULTI -FUNCTION
MEGA-FUNCTION
8
ICs to Systems Applications
Design Multifunction Nano-materials
System Interconnections Thermal
9
Two Types of Components

• Devices
• 10 of System
• Non-Devices System Components
• 90 of Systems

10
3 Barriers to Systems
WAFER
IC PKG.
System Interconnects
Board
SYSTEMPKG.
Discretes
11
Georgia Tech-PRC Vision of 3D Systems

• SYSTEMS
• Consumer
• Computer
• Health Care
• Energy

Passives R, L, C, Antennas
Packages and Boards
3D Systems by SOP Fab
Thermal Materials and Interfaces
Power Sources
System Interconnections reliability
System design Tools
3D Systems
12
Miniaturization of ICs
13
Georgia Tech-PRC Vision of 3D Systems
ICs
14
ICs

• IC integration continues
• Most ICs are commodities
• Performance beyond 32 nm is limited
• Integration of dissimilar ICs expensive
• Wafer fab investments very high
• Design technology issues
• Future uncertain Beyond 32-22 nm

15
2D ICs MCMs
16
Highly Integrated System Technologies by IBM,
Hitachi, Fujitsu, and NEC in 1990s
A.) Industrys First MCM (IBM),1982
B.) 61 Layer LTCC/Cu-MCM(IBM)1992
17
3D ICs
18
Why 3D ICs?

• Design Efficiency
• Heterogeneous ICs
• Higher chip yield vs. large SOC
• Logic-SOA
• Analog- past Generation
• Low Interconnect delay
• Higher bandwidth
• Less power
• Miniaturization
• Faster Time to market
• Ultimately Lower Cost

19
3D IC Package Technology Evolution
SIP Si Substrate Technologies
1970
1980
2000
2010
Year
20
Miniaturization Approaches in 3D ICs

• IC to 32nm to ?
• Thinned ICs
• 3D Stacked ICs with WB FC
• 3D ICs with TSV

3D ICs for Transistor Density
21
Impact of 3D ICs Profound at IC level but
Limited Without 3D Systems
1. ProcessorPackage
3. Discrete Components
2. Stacked Memory
4. Connectors Batteries
22
3D ICs without 3D Systems Creates Gap
108
107
106
105
Transistors/cm3
Component Density or
104
System Integration Law
103
102
10
1971
1980
1995
2020
1990
Source IBM, Intel
23
3D ICs without 3D System
24
3 Types of TSVs

• TSV as an interconnection CIS PA
• TSV in 3D with similar ICs to improve density
  Memory
• Cost of TSV vs. WB
• Beyond 64GB Chip
• TSV in 3D with dissimilar ICs to replace SOC
• Impacts FEOL and BEOL
• Partitioning of system

25
3D Systems

• Why 3D Systems?
• Can we miniaturize the entire system for better
  cost ,functionality, performance and reliability?
• 3D ICs miniaturize only 10 of system
• Need to miniaturize the 90 system

26
Typical Mobile Phone System

• Multiple Functions
• Digital Computing
• RF Communication
• GSM/CDMA/GPRS/EDGE
• WLAN/WiMAX
• Bluetooth
• GPS
• TV Tuner
• Optical/Imaging
• Sound/Voice
• Video/Photo
• Data
• I/O
• Gaming/Entertainment

27
Georgia Tech-PRC Vision of 3D Systems
Passives R, L, C, Antennas
Packages and Boards
3D Systems by SOP Fab
Thermal Materials and Interfaces
Power Sources
System Interconnections Reliability
3D Systems
System design Tools
28
System Partitioning into System Components
29
3D Systems Start with Interposer

• Organic Interposers are limited by
• Wiring and I/Os
• Cost
• Si Interposers
• High cost

30
Basis of 3D Systems Nano-components

• Passives
• Interconnections
• Thermal interfaces
• Batteries

31
Nano-materials to Nano-systems
32
Single Technology Platform for Systems
ICs and 3D ICs

3D Systems
Source IBM, Intel
33
Examples of 3D System Technologies _at_ micro and
nanoscales
34
Interposer with Nanotechnologies
Nanocapacitors for volumetric efficiency Nanostru
ctured copper for microvia reliability and
interconnections Nanostructured dielectrics,
underfills and encapsulants for enhancing
reliability with strength, High Tg and moisture
resistance Self-healing polymers to extend
fatigue life (crack-arrest with
nanopolymer) Nanocomposite (high E, low CTE and
thin) wafer for system
nano-composite
35
Polymer-based RF Capacitor Examples
DuPont IBM
Nokia, PRC
Thermal stability
RF passives on LCP, FR4 (PRC)
RF materials LCP, PTFE composites
36
Sputtered Resistor Examples
Foil transfer (Gould, Shipley)
OhmegaPly Resistor
Boeing TaN Resistor
INTARSIA RLC Network
37
Thin Film Resistor Examples
Electroless Plated Resistor Process
Electroless Ni alloy resistors 50-100 ohms/square
Foil Transfer Process
Foil transfer process 1-10 k Ohms/square TCR 100
ppm/C
Polymer thick film (PTF) Printing Process
Printed polymer thick film resistors 500 10K
ohms TCR 300 ppm/C
38
Emerging Trend to Ultra Thin Film Capacitors
NXP
39
High Q on Silicon - Examples
High Q with spacers
High Q with silicon trenches, GT, Ayazi
DIMES
High Q with HRPS and glass
High Q with through-substrate trench
40
Examples of Organic-compatible Capacitors
Motorola Mezzanine Cap 15 Tol, 450 pF and Q
20
Oak-Mitsui 310 pF/cm2
3M C-Ply, 0.9 nF/cm2
DuPont Sintered paste 300 nF/cm2 BDV gt20 V
Anodization (Ta2O3) U. Arkansas 300-400 nF/cm2
high BDV
High k thin films on organic substrates (PRC)
41
Trend to Nano-decoupling Capacitor
High surface area Nanoelectrodes

• Thinner Dielectrics
• Stable properties with frequency
• Take advantage of new polarization mechanisms
• Interfacial polarization
• Electrical double layer type polarization

42
Interfacial Polarization with Nano-capacitors
Dielectric properties of Al-filled composites
Micrograph of the cross section of a 40 nm Al2O3
coated 3.0 µm spherical Al particle.
J. Xu, C.P. Wong, Appl. Phys. Lett., 87, pp.
082907 (2005).
43
C. Thermal Materials Interfaces Requirements
250
NTIM
200
LF TIM
150
STIM
Cooling Capability W
PTIM
100
Bare
die
50
0
2000
2002
2004
2008
2012
44
Metallizable CNT for Improved TIM

• CNT carpets (30006000 W/mK) as TIM
• Patterned growth of CNTs
• Transfer and assemble lt200C
• Decrease the thermal contact resistance

45
System Interconnections
IC
I level
Package Interposer
II level
Interconnect Board
I level Challenges 40-100 micron pitch (Area
array) 106 A /cm2
20-40 micron pitch (Peripheral) 106 A /cm2
10-20 micron pitch (TSV,3D) 106 A /cm2
II level Challenges 200-500 micron pitch 104
A/cm2
45
46
Photo-definable Low CTE Nano Underfills

• Improved thermo-mechanical properties.

47
Nano-Cu Offers Better Fatigue and Strength than
Micro-Cu
48
Fatigue of Nanoscale Materials
Experimental Data from Nanocopper and Microcopper
10-3
450
Crack growth rate (mm/cycle)
Nano Cu
Micro Cu
Stress Amplitude (MPa)
10-4
300
Nano Cu
10-5
150
Finegrain Cu
Micro Cu
10-6
0
2.0x107
100
0.5 x104
1.0 x 106
10
DK Measure of stress intensity at crack tip
(MPa vm)
Number of Cycles
Shubhra Bansal, GT-PRC
49
Particle-based Nano-interconnections
50
Nano-composites for Moisture Resistance
Water permeability as function of filler content
Claypolymer nano-composites
Azom.com
Chugang Hu, Jang-kyo kim, HUST
51
Super-hydrophobic Surfaces

• Nano-porous surface structure followed by
  fluorosilane treatment to achieve stable
  transparent superhydrophobic silica film
• Composite materials PDMS/silica nanoparticle for
  self-recovering superhydrophobic surfaces.

C P Wong
52
Self-healing of Cracks in Nanocomposite Polymers

• A encapsulated liquid monomer healing agent is
  embedded in a structural polymer matrix
  containing a catalyst capable of polymerizing the
  healing agent.
• When the material is damaged cracks occur,
  rupturing the microcapsules and releasing the
  healing agent into the crack plane through
  capillary action.
• The healing agent contacts the catalyst,
  triggering polymerization that bonds the crack
  faces closed.

Kessler, Iowa State
53
Biocompatible Surfaces and Coatings
Anti-inflammatory Coating
Neuroelectrode and Package-tissue Interfaces
Inflammation can isolate the electrode from the
neurons Immobilize anti-inflammatory coatings on
the electrode surface Coat with molecules which
enable tissue integration
Modulated Neural Interfaces
Superhydrophobic Surfaces
Contact angle gt 160 Low adhesion Nanostructured
morphology
Modulation of scarring around implanted
electrodes using coating
54
PRC Focus ZnO Nanowire Sensors

• ZnO nanowire/nanobelt
• Wideband gap semiconductor
• Piezoelectric material
• Bio-compatible material

Electrical Impedance Measurements
The impedance change is used as a measure of
molecular hybridization.
Applications The applications of this detection
system include early detection of breast cancer,
food and drink pathogens such as E. coli and
Salmonella.
55
CNT-based ECS Working Electrodes
Vertically Aligned CNTs

• CNT - Electrocatalytic surface for oxidation of
  biomolecules
• Stable electrochemical activity
• Minimum biofouling
• High electrical conductivity for current
  transduction
• Increased sensitivity from high contact area
  (nanostructure)

Eg peak from oxidation of guanine Glutamate
amperometry
Lower detection limit Miniaturization
56
Georgia Tech-PRC Vision of 3D Systems

• SYSTEMS
• Consumer
• Computer
• Health Care
• Energy

Passives R, L, C, Antennas
Packages and Boards
3D Systems by SOP Fab
Thermal Materials and Interfaces
Power Sources
System Interconnections reliability
System design Tools
3D Systems
57
Summary

• System miniaturization allows disruptive
  functionality beyond 3D ICs
• Low- cost 3D- Interposer is starting point for
  3D systems
• Novel thin film and nano- technologies provide
  the necessary breakthroughs to 3D systems.
• Georgia Tech to launch Industry-University
  Consortium in low cost 3D Glass-Silicon
  Interposer
• Technology, July 2009