Optoelectronic Devices and Packaging:

1
Tutorial 1998
Optoelectronic Devices and Packaging VCSEL
Technology Tutorial Leader Michael
Lebby Phoenix Applied Research
Center Motorola 2100 East Elliot Road, Tempe, Az
85284 email AYPH10_at_email.mot.com Voice (602)
413-4826 fax 4952
Tutorial Objective
Introduction Tutorial Objective Optoelectronic
devices and packaging have found increasing use
in many new products over the last 20 Yrs. This
tutorial primarily will focus on semiconductor
laser based technology with particular emphasis
on emerging new technologies such as the Vertical
Cavity Surface Emitting Laser (VCSEL) and how to
take advantage of its uniqueness in packaging.
The tutorial will look at the driving factors
required for low cost high volume VCSEL based
packages and what impact they will have in
tomorrows products. As there are many packaging
solutions for VCSEL based technology proposed,
the course will show the relative merits of
popular new technologies with respect to high
volume and low cost manufacturing.
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Tutorial Objective

• Tutorial Objective
• Providing information that gives the attendee a
  working knowledge on
• Commercial Edge Emitter laser technology
• What a EE laser chip is and looks like
• How a EE laser chip is packaged
• VCSEL technology why the euphoria
• What a VCSEL chip is...
• How VCSELs are packaged...
• VCSEL Performance
• VCSEL Applications... today...tomorrow
• Technical Challenges
• Commercial and market impact

Section 1

• Section 1
• VCSEL Technology
• Device Status
• Package Status
• Section 2
• VCSEL Technical Issues
• Fabrication and Characterization
• Testing and Reliability
• Manufacturing

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Abbreviation

V
ertical
C
avity
S
urface
E
mitting
L
aser


VCSEL (commonly pronounced 'vixel')


Other names used


Veesel (V-SEL)


VCSELD (V-seld)


VCL (Vixel)


Surface Emitter


Micro-resonator
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Why
VCSELs
over Edge Emitters (
EEs
) ?

Component Cost Impact



Fabricated like
LEDs
-gt first laser with potential die cost to
approach
LEDs
(with high volume)


Wafer probing, no cleaving,
GaAs
saw, surface light emission


VCSELs
in high volume markets the die cost will be
similar to CD laser chips as the cost is in the
package



Die cost is sensitive to real estate (VCSEL
advantage)


Epi
wafer costs are more for VCSEL (EE advantage)


Only if the package, probe,
aligment
procedures are made LED-like will the VCSEL hope
to reach the low

cost levels expected



Packaging Cost Impact


Low volume fiber optics markets EE package cost
is 80-90 package


VCSEL should reduce this through simplified
packaging/coupling/KGD


High volume markets requires passive alignment
and KGD before package


VCSEL has potential to achieve these goals with
less volume than the EE


Trend towards LED-like packaging means plastic
alternatives are needed


System Cost Impact


VCSEL packages are smaller -gt smaller systems


VCSEL has lower power drain -gt longer battery
life on systems


VCSEL can be flip-chip packaged -gt lower cost
systems


VCSEL has circular output beam -gt less lenses in
systems


VCSEL Arrays are natural -gt provides degree of
freedom in design
EE Laser and VCSEL Output Characteristics
VCSEL
Edge emitting laser

Auto-power control (can the VCSEL avoid it?)
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VCSEL Device Status

Structures


Planar Proton Implanted


Index Guided Ridge Waveguide


Hybrid Mirror


Intracavity contact


Lateral Oxide


Native Oxide


Wafer Fused


What is commercially available today?


Proton Implanted


Ridge Waveguide
Common device Cross-sections
Proton Isolated Planar VCSEL
Ridge Wave Guide VCSEL
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Visible VCSEL structure
After R.
Schneider
(1995)
Partial dielectric mirror and partial
semiconductor mirror
After R.Morgan (1995)
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(No Transcript)
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Small signal modulation of a
lateral oxide confined VCSEL
After B.
Thibeault
, UCSB

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Native oxide mirror VCSEL
After M.H.
MacDougal
(1995)
Wafer fused structure for long wavelength VCSEL
After J.J.Dudley (1994)
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Commerical VCSEL Status

After Strategies Unlimited 1996
VCSEL Package Status

Packages that are being used for VCSELs

TO-can wire-bond


Plastic Leadframe Flip-chip


TAB Flip-chip


C4 Flip-chip


Efforts to address VCSEL arrays have been the
focus of many RD labs

over the last 5Yrs


A few examples are discussed


Companies participating include AMP, Gore
Photonics, MITEL, HP, Honeywell, IBM,

Lucent, Micro-optical, Picolight, SDL, Vixel,
Xerox amongst others.


Motorola's parallel link is productized (400Mbps
_at_ 10channels, 300m)


Integrated (Simplify Packaging)


Detector


Lens