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InGaAs and GaInNAs(Sb)Advanced LIGO Photodiodes
David B. Jackrel, Homan B. Yuen, Seth R. Bank, Mark A. Wistey, Xiaojun Yu, Junxian Fu, Zhilong Rao, and James
S. Harris, Jr.Solid State Research Lab, Stanford University
LSC Meeting – LHOAugust 16th, 2005
LIGO-G050435-00-Z
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Outline
Introduction AdLIGO Photodiode Specifications Device Materials Device Design
GaIn(N)As(Sb) Materials & Device Results
Conclusion
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Advanced LIGO Schematic
Power Stabilization
Auxiliary Length Sensing
High-Speed
Low Power
Commercial Device
180 W
Low Noise
Iph ~ 200 mA
Commercial Device?
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LIGO AS-Photodiode Specifications
I-LIGO Advanced LIGO
DetectorBank of
6PDsDC -
Readout
RF – Readout
Steady-State “Power” (mW)
60030 – 100
(same as DC)
Operating Frequency
30 Mhz100 kHz 200 MHz
Quantum Efficiency
80% 90%(same as DC)
DamageThreshold
(MW/cm2)
< 5 < 50(same as DC)
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1 eV Materials: InGaAs & GaInNAs
GaInNAs(Sb)
25% InGaAs
1064nm light 1.13eV
º Ge
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Metamorphic-InGaAs vs. GaInNAsDouble Heterostructres
1m2m I- GaInNAs(Sb)
8% In, 2% N, (4% Sb)I- In0.25Ga0.75As
GaInNAs(Sb) MBE growth with RF-Plasma source for N
Sb surfactant effects improve thin strained nitride films
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Conventional PD
Adv. LIGO Back-Illuminated PD
High Power Linear
Response High Speed
Back-Illuminated Photodiodes
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Outline
Introduction
GaIn(N)As(Sb) Materials and Device Results
Materials Characterization Summary Dark Current Bandwidth Quantum Efficiency Saturation Power Level
Conclusion & Future Work
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Materials Characterization Summary
PL Intensi
ty(A.U.)
Relaxation
(%)
Absorption
(%)TDD
(cm-2)
Trap Densit
y (cm-3)
MM- InGaAs 24.1 88.9 96% 1e7 2.0e13
GaInNAs 2.2 4.3 60% ~1e5 1.1e14
GaInNAs(w/
Deflection Plates) 8.5 - 70% ~3e5 -
GaInNAsSb(w/ D.P.) 1.1 44.6 80% < 1e5 -
XRD-Reciprocal Space Map (224)
Photoluminescence (PL) SpectraAbsorption SpectraDeep-Level Transient Spectroscopy (DLTS)
A
B
A
B
Spectral Cathodoluminescence (CL) Imagingto determine Threading Dislocation Density (TDD)
Intensity Peak Energy
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Dark Current Density:GaIn(N)As(Sb) Devices
- J d
k (
A/c
m2)
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MM-InGaAs: 3dB Bandwidth
= 3 mm MM-InGaAs PD
BW ~ 1/RCBW > 200 MHz
= 400 m
Psat ~ 10 mW
AdLIGO PD Specifications:
3-dB Bandwidth Sat. Power
DC-Scheme: 100 kHz 30 – 100 mWRF-Scheme: 200 MHz
AdLIGO RF-Readout Challenging for PDs!
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InGaAs & GaInNAs PDs – IQE(w/ FCA & Incomplete Absorption)
AdLIGO Requirement
inphotons
outcurrentQE
Int.
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GaIn(N)As(Sb) PD QE
GaInNAs
GaInNAsSb*
InGaAs
(* scaled to account for FCA in thick substrates)
Int.
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Photodiode Saturation Power
GaInNAs
GaInNAsSb*
InGaAs
Bias V: 3 ~ 8 V(* scaled to account for FCA in thick substrates)
LIGO GW-PD Requirement
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Photodiode Results Summary
Materials Parameters Photodetectors
Abs.
(%)
Relax.
(%)TDD
(cm-2)
Trap Density (cm-
3)IQE(%)
Jdk
(A/cm2)
MM- InGaAs 96% 88.9 1e7 2.0e13 75% ~ 10
GaInNAs 60% 4.3 ~1e5 1.1e14 62% ~ 0.1
GaInNAsSb 80% 44.6 < 1e5 -56%
(scaled) ~ 1
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Conclusion
AdLIGO AS-PD Specification
B-I PDs
Developed at Stanford
F-I PDs
Commercial devices
Saturation Power
(mW)30 - 100 ~ 150 100 ~ 200
Quantum Efficiency 90 %
75 %( 90 % w/ substrate
removal)
~ 90 %
Bandwidth
(MHz)
100 kHz
( 200 MHz RF-scheme)
4 1 ~ 10
Damage Threshold
(MW / cm2)
< 5(w/ 1 s shutter & 1 mm spot)
Modeling
~ 3 (w/ 1 mm
spot)
Modeling
~ 0.4 (w/ 1 mm
spot)
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AdLIGO Photodiode Development: Future Work
Substrate removal 90 % QE
High-Temperature Packaging LLO or LHO Damage Threshold Tests? Compatible with other experiments (GEO-600, MIT?)
Surface Uniformity & Noise Characterization GEO-600
Multi-Element Sensors? Additional pointing information Spatial mode information
Fabricate AdLIGO Photodiodes
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Acknowledgements
National Science Foundation (NSF); this material is based on work supported by the NSF under grants 9900793 and 0140297.
Aaron Ptak, Manuel Romero and Wyatt Metzger at National Renewable Energy Labortatory (NREL) in Golden, CO
Gyles Webster at Accent Optical in San Jose, CA
Thank You
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Extra slides
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Molecular Beam Epitaxy (MBE)
Effusion cells for In, Ga and Al
Cracking cell for As and Sb
RF-Plasma N cell
Deflection Plates (DP) on Plasma Source
protect growth surface from ion damage
+ V
- Vsubstrate
Nitrogen cell
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Double-HeterostructurePIN Photodiodes
N- and P- transparent
Absorption occurs in I-region
where E-field is large
n-
i-
p-
0 1 2 3 m
2
eV
1
0
-1
-2
InGaAs DH-PIN device simulated by ATLAS (Silvaco)
light
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Lattice-Mismatched Epitaxy
misfit dislocation
afilm
asubstrate
afilm > asubstrate
h < hc
h > hc
hc critical thickness
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Materials Results Summary
PL Intensi
ty(A.U.)
Relaxation
(%)
Absorption
(%)TDD
(cm-2)
Trap Densit
y (cm-3)
MM- InGaAs 24.1 88.9 96% 1e7 2.0e13
GaInNAs 2.2 4.3 60% ~1e5 1.1e14
GaInNAs (DP) 8.5 - 70% ~3e5 -
GaInNAsSb 1.1 44.6 80% < 1e5 -
