Silicon photonics:
a new technology platform to enable
low cost and high performance
photonics
L P
L.
Pavesii
L. Pavesi
18-11-10
Outline
•
•
•
•
•
Silicon Photonics
State of the art
Sili
Silicon
Photonics
Ph t i ffor llab-on-a-chip
b
hi
NanoSilicon photonics
Conclusion
L. Pavesi
18-11-10
Outline
•
•
•
•
•
Silicon Photonics
State of the art
Sili
Silicon
Photonics
Ph t i ffor llab-on-a-chip
b
hi
NanoSilicon photonics
Conclusion
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Objective: reduce the cost per single transistor
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29 January 1969
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18-11-10
vs Silicon Photonics
vs.
Silicon Photonics
LD,PD, microrings,
….
Silicon
CMOS
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18-11-10
Silicon photonics
Photonic devices produced within
y and with
standard silicon factory
standard silicon processing
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18-11-10
Silicon pro’s
pro s and cons
•
•
•
•
Transparent
p
on 1.3-1.5 μ
μm
CMOS compatibility
Low cost
High index contrast, small footprint
•
•
•
•
No electro-optic effect
No detection in 1.3-1.5 μm region
High index contrast coupling
Lacks efficient light emission
L. Pavesi
18-11-10
The Opportunity of Silicon
Ph
Photonics
i
• Enormous ($ billions) CMOS infrastructure, process
learning, and capacity
•
Draft continued investment in Moore’s law
• Potential to integrate multiple optical devices
• Micromachining could provide smart packaging
• Potential to converge computing & communications
L. Pavesi
18-11-10
To
o benefit
be e t from
o this
t s optical
opt ca wafers
a e s
must run alongside existing product.
CMOS PHOTONICS
Cost = paradigm change
• 200 mm Si wafer has 125,000 - 0.5 mm sized
dies
• Cost processed CMOS wafers $2,000,000
• Cost per die: $16
• Laser size: 10x100 microns.
• Cost per laser: $ 0.064
• This is just like estimating the cost of transistors.
They are free. Only the PIC cost matters.
• Emphasis is moved from components to the
system
L. Pavesi
18-11-10
Silicon photonics
Basic building blocks
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Modulator
ƒ Because of its crystal structure, silicon is not a
useful conventional electro-optic material
ƒ Because of its indirect bandgap, silicon has no
near bandgap nonlinearities
ƒ Thermo-optical effect is strong but slow
The only effect that is left is the free
carrier or Drude effect
[
[
−22
−18
Δn = − 8.8 x 10 Δ N + 8.5 x 10 (Δ P)
−18
−18
8
.
5
10
6
.
0
10
(Δ P)
x
x
Δα =
ΔN +
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18-11-10
]
]
0.8
R.A. Soref and B.R. Bennett, IEEE JQE 23, 123 (1987)
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18-11-10
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18-11-10
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18-11-10
Photodetection
Ge
•
Silicon does not absorb IR well
Æ Use hybrid approach
Æ Use
U SiG
SiGe or strained
i d Ge
G
Æ Use damaged silicon
Si
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18-11-10
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18-11-10
Ge photodector
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IEF-LETI
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III-V heterogeneous
integration for the laser source
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III-V heterointegration for the
laser source
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18-11-10
Where should we integrate the
photonics layer ?
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18-11-10
Options 1
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18-11-10
Options 1
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18-11-10
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18-11-10
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18-11-10
This requires
Spotsize conversion structures
Lateral coupling
Vertical coupling
fiber
φ
air
d
g
r
h
x
y
• typically based on inverted tapers
• spotsize:
t i
~3
3 µm
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18-11-10
z
• typically based on gratings
• spotsize:
t i
~ 10 µm
e
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18-11-10
Outline
•
•
•
•
•
Silicon Photonics
State of the art
Sili
Silicon
Photonics
Ph t i ffor llab-on-a-chip
b
hi
NanoSilicon photonics
Conclusion
L. Pavesi
18-11-10
Explosion of silicon photonics
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From Building Block Research
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18-11-10
To Large scale integration
Optical Fiber
Multiplexor
25 modulators at 40Gb/s
25 hybrid lasers
A future integrated 1 Tb/s optical link
on a single silicon chip
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18-11-10
46
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18-11-10
Silicon Photonic Link
50Gbps
50Gb
Multichip approach
Driver 45 nm CMOS
Photonic 90 nm CMOS
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18-11-10
Outline
•
•
•
•
•
Silicon Photonics
State of the art
Sili
Silicon
Photonics
Ph t i ffor llab-on-a-chip
b
hi
NanoSilicon photonics
Conclusion
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18-11-10
Nanosilicon photonics:
a platform where silicon nanoclusters
enable new functionalities in silicon
photonics
h t i
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18-11-10
Silicon Nanophotonics
• Confine carriers on nanoscale
dimensions
• Confine photons on nanoscale
dimensions
10 μm
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18-11-10
Silicon quantum dots
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18-11-10
50 nm
Silicon quantum dots
Egc-Si
Bulk Silicon:
Indirect band
band-gap
gap
inefficient light emitter
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18-11-10
Nanocrystalline-Si:
Direct-gap
g p due to QCE
Q
Strong visible light
emission
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18-11-10
Purcel effect
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Integration of microdisk with a
waveguide
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THE all SILICON TR
RANSC
CEIVER
pHotonics ELectronics functional
Integration on CMOS
CMOS capacitor based on Si-NC gate
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25/02/2010
Marconi, Anopchenko
59
RANSC
CEIVER
THE all SILICON TR
pHotonics ELectronics functional
Integration
CMOS
Light
EmittingonProprieties
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18-11-10
Forward Bias
Reverse Bias
Poly p-type
Luminescent
Region
-5 V
Si substrate n-type
Al
+
p-type
silicon
wafer
-
Active
Si-NC
n-type
polysilicon
∼100
nm
(2 nm SiO2 / 3 nm SRO)
1
Graded energy gap
(2 nm SiO2 / 4 nm SRO)
0.1
0.2
Power effficiency (%)
2
Optical pow
wer density (μW / cm )
pHotonics ELectronics functional
Integration on CMOS
0.01
0.0
-3
10
-2
10
1
-1
10
2
Current density (mA / cm )
-3
10
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18-11-10
0.1
-2
-1
1
10
10
2
Current density (mA / cm )
1
10
THE all SILICON TR
RANSC
CEIVER
pHotonics ELectronics functional
Integration on CMOS
L. Pavesi
18-11-10
Forward Bias
Reverse Bias
Poly p
p-type
type
Si substrate n-type
Al
25/02/2010
Detection
R i
Region
pHotonics ELectronics functional
Integration on CMOS
TTL in
TTL out
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18-11-10
25/02/2010
Marconi
63
All optical switching with
silicon
ili
nanocrystals
t l
n=n0+n2 I
α=α0+β I
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18-11-10
T = 1 − 2ξ (1 − ξ )(1 − cos Δϕ )
Comparison to other nonlinear
materials
i l
Silica
n2= (1.54x10-16) cm2/W [3,4]
Bulk Silicon
n2= (4.5x10-14) cm2/W [3,4]
GaAs
n2= (1.59x10-13) cm2/W [5]
Si-ncs
n2= (2 ÷ 8x10-13) cm2/W [present work]
[3] Handbook of Nonlinear Optics
[4] Adair R. et al., Physical Review B, 39, 3337, (February 1989).
[[5]] M. Dinu et al.,, Applied
pp
Physics
y
Letters,, 82,, 2954 ((2003).
)
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18-11-10
All op
optical
ca sswitching
c g
Si nanocrystals activated slot waveguides
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A. Martinez et al. Nanoletters (2010)
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18-11-10
A. Martinez et al. Nanoletters (2010)
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
L. Pavesi
18-11-10
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
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18-11-10
Photon electron energy
conversion
32.9%
Unabsorbed energy loss
18.7%
Heat loss
46.8%
Other losses
1.6%
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
L. Pavesi
18-11-10
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
Secondary carrier
generation
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
Silicon nanocrystals
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK
Improved photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK
(b) PDS-2
TSRO
Optica
al function
0.8
0.3
RSRO
ASRO
0.6
0.2
PR
PRARC
0.4
ΔηINT
0.2
0.0
400
0.1
0.0
500
600
Wavelength (nm)
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18-11-10
P
Photorespon
nsivity (A/W))
Internal qu
uantum efficciency enhancement
1.0
700
A maximum enhancement of the internal
quantum efficiency of 14%
Improve photovoltaic efficiency by
appl ing novel
applying
no el effects
at the limits of light-matter
g
interaction
Secondary carrier
generation
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18-11-10
Ryan, Anopchenko, Marconi – APP FBK - Minhaz
Cross section of the device
Al (1%Si) 500 nm
Al (1%Si) 500 nm
SiO2 (TEOS) 120 nm
LOCOS
500 nm
LPCVD Si3N4 50 nm
n-type Poly-Si 30 nm
Si--rich Oxide 50 nm
Si
P-type Si substrate
Al (1%Si) 500 nm
Device area = 320 μm X 320 μm
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK - Minhaz
LOCOS
500 nm
Cross section of the device
Al (1%Si) 500 nm
Al (1%Si) 500 nm
SiO2 (TEOS) 120 nm
LPCVD Si3N4 50 nm
n-type Poly-Si 30 nm
Si--rich Oxide 50 nm
Si
LOCOS
500 nm
absorption
P-type Si substrate
Al (1%Si) 500 nm
Device area = 320 μm X 320 μm
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK - Minhaz
LOCOS
500 nm
Cross section of the device
Al (1%Si) 500 nm
Al (1%Si) 500 nm
SiO2 (TEOS) 120 nm
LOCOS
500 nm
LPCVD Si3N4 50 nm
n-type Poly-Si 30 nm
multiplication Si
Si--rich Oxide 50 nm
absorption
P-type Si substrate
Al (1%Si) 500 nm
Device area = 320 μm X 320 μm
L. Pavesi
18-11-10
Ryan, Anopchenko, Marconi – APP FBK - Minhaz
LOCOS
500 nm
P
Photo-cu
urrent (IL - ID) (m
mA)
IR response in Γ3N
10
1.0
0.5
> 1200 nm
00
0.0
-0.5
-1.0
10
-1.5
-2.0
20
-5
-4
-3
-2
-1
A li d Bias(V)
Applied
Bi (V)
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18-11-10
0
P
Photo-cu
urrent (IL - ID) (m
mA)
IR response in Γ3N
10
1.0
0.5
Voc= 500 mV
> 1200 nm
00
0.0
-0.5
633 nm
-1.0
10
488 nm
-1.5
-2.0
20
-5
-4
-3
-2
-1
A li d Bias(V)
Applied
Bi (V)
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18-11-10
0
Phhoto-current (IL - ID) (m
mA)
IR response in Γ3N
10
1.0
0.5
Voc= 500 mV
> 1200 nm
00
0.0
-0.5
633 nm + 1200 nm
-1.0
10
488 nm + 1200 nm
-1.5
-2.0
20
-5
-4
-3
-2
-1
A li d Bias(V)
Applied
Bi (V)
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18-11-10
0
Phhoto-current (IL - ID) (m
mA)
IR response in Γ3N
10
1.0
0.5
Voc= 500 mV
> 1200 nm
00
0.0
-0.5
633 nm + 1200 nm
10 %
-1.0
10
488 nm + 1200 nm
-1.5
-2.0
20
-5
-4
-3
-2
-1
A li d Bias(V)
Applied
Bi (V)
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0
Solar cell with an internal gain mechanism
Secondary carrier
ge e at o
generation
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18-11-10
Ryan, Anopchenko, Marconi – APP FBK - Minhaz
Outline
•
•
•
•
•
Silicon Photonics
State of the art
Sili
Silicon
Photonics
Ph t i ffor llab-on-a-chip
b
hi
NanoSilicon photonics
Conclusion
L. Pavesi
18-11-10
Conclusions:
• Silicon photonics is a mature technology
• Silicon photonics allows fabricating thousands
of p
photonic components
p
in a single
g chip
p
• Silicon photonics merges electronics and
photonics to enable novel functionalities
p
• Silicon photonics is not only bulk Silicon
(nanosilicon, strained silicon,
silicon/germanium, germanium, ….)
• Silicon photonics is not only optical
communication is much more
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18-11-10
Bottom line:
• Each time the market catches size
Silicon is the solution
• If you may want to compete with silicon
silicon,
do not! Silicon will always make it
L. Pavesi
18-11-10
L. Pavesi
18-11-10
Acknowledgments
•
•
•
•
•
EC: Helios, LIMA, Wadimos, Positive
PAT: Gopsi, Naomi
MAE: Italy-turkey, mexico, romania
HCSC project and OptoI
ITPAR
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18-11-10
Acknowledgments
g
L. Pavesi
18-11-10