Advanced LIGO High-Power Photodiodes
description
Transcript of Advanced LIGO High-Power Photodiodes
![Page 1: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/1.jpg)
STANFORD
Advanced LIGO High-Power Photodiodes
David Jackrel, PhD Candidate
Dept. of Materials Science and Engineering
Advisor: James S. Harris
LSC Conference, LLO
March 17th-21st, 2003
LIGO-G030069-00-Z
![Page 2: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/2.jpg)
STANFORD
Outline
Introduction
High-Power Results
High Efficiency Process
Predictions
![Page 3: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/3.jpg)
STANFORD
Photodiode Specifications
Parameter LIGO I Advanced LIGO
Steady-State Power 0.6 W ~1 W
Operating Frequency 29 MHz 100 kHz
~ 180 MHzQuantum Efficiency 80% 90%
Detector Design
Bank of 6(+) PDs 1 PD
![Page 4: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/4.jpg)
STANFORD
GaInNAs vs. InGaAs
GaInNAs
25% InGaAs
53% InGaAs
1064nm light 1.13eV
![Page 5: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/5.jpg)
STANFORD
InGaAs vs. GaInNAs PD Designs
2 m
GaInNAs lattice-matched to
GaAs!
![Page 6: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/6.jpg)
STANFORD
Heterojunction Band Gap Diagram
N-layer:
In.22Al.78As or GaAs
Eg2=2.0-1.4eV
P-layer:
In.22Al.78As or GaAs
Eg2=2.0-1.4eV
I-layer:
In.22Ga.78As, or Ga.88In.12N.01As.99
Eg1=1.1eV
n-
i-
p-
InAlAs and GaAs transparent at 1.064m
Absorption occurs in I-region (in E-field )
![Page 7: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/7.jpg)
STANFORD
Rear-Illuminated PD Advantages
Conventional PD Adv. LIGO Rear-Illuminated PD
High Power Linear
Response High Speed
![Page 8: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/8.jpg)
STANFORD
DC Device Response
![Page 9: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/9.jpg)
STANFORD
DC Device EfficiencyE
xt.
Eff
icie
ncy
Optical Power (mW)
Bias (Volts)
![Page 10: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/10.jpg)
STANFORD
High Efficiency Detector Process (1)
1. Deposit and Pattern P-Contact
2. Etch Mesa – H2SO4:H2O2:H20 and Passivate in (NH4)2S+
3. Encapsulate Exposed Junction
4. Flip-Chip Bond
- N+ GaAs Substrate
- Epitaxial Layers
- Au Contacts
- Polyimide Insulator
- SiNx AR Coating
- AlN Ceramic
![Page 11: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/11.jpg)
STANFORD
High Efficiency Detector Process (2)
6. Deposit AR Coating & N-Contact
7. Saw, Package and Wire-Bond
- N+ GaAs Substrate
- Epitaxial Layers
- Au Contacts
- Polyimide Insulator
- SiNx AR Coating
- AlN Ceramic
5. Thin N+ GaAs Substrate
![Page 12: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/12.jpg)
STANFORD
Surface Passivation Results
![Page 13: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/13.jpg)
STANFORD
Predictions
Diameters 3mm 4.5mm 150um
Saturation Power
Devices Old New New
300mW ~1W ~2mW
Bandwidth
Devices Old New New
3MHz ~1MHz ~1GHz
![Page 14: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/14.jpg)
STANFORD
Conclusion
High-Power Results 300mW (@ 3MHz B.W.) 60% External Efficiency
High-Efficiency Process < -30 Volts realized (on un-mounted
devices) Working out processing
Predictions (by Next LSC…) 1 Watt (@ 1MHz B.W.) 90% External Efficiency
![Page 15: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/15.jpg)
STANFORD
MBE Crystal Growth
Effusion cells for In, Ga, Al
Cracking cell for As Abrupt interfaces Chamber is under
UHV conditions to avoid incorporating contaminants
RHEED can be used to analyze crystal growth in situ due to UHV environment
T=450-600C
N Plasma Source
Atomic source of nitrogen needed Plasma Source!
![Page 16: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/16.jpg)
STANFORD
P-I-N Device Characteristics
Large E-field in I- region
Depletion Width Width of I- region
RC time constant
Absorbs a specific
1
IW
IsJ
Js
WAKC
CR
/0
![Page 17: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/17.jpg)
STANFORD
Full Structure Simulated by ATLAS
![Page 18: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/18.jpg)
STANFORD
DC Device Efficiency
![Page 19: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/19.jpg)
STANFORD
Free-Carrier Absorption
(1-T-R) and (1-T-R)/(1-R)
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
850 950 1050 1150 1250 1350 1450 1550 1650 1750
Wavelength (nm)
Ab
sorp
tio
n (
no
rm.)
GaAs N+
GaAs S-I
GaAs N+ (W)
GaAs S-I (W)
32.9%
N+
S-I
![Page 20: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/20.jpg)
STANFORD
Surface Passivation Results (2)
![Page 21: Advanced LIGO High-Power Photodiodes](https://reader036.fdocuments.us/reader036/viewer/2022062304/56813aba550346895da2c37e/html5/thumbnails/21.jpg)
STANFORD
(NH4)2S+ Surface States
(Green and Spicer, 1993)
GaAs(111)A GaAs(111)B