Transcript CODES

CODES:
ESA Project
22381/09/NL/PA
component degradation
simulation tool
Outline
• Aim of activity
• Basic mechanisms
• The Framework and Work principles
• SEU and SEL Monitors
• Further Work
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Aim
• Integrated framework for SEE rate prediction for devices under
different radiation environments
• Enabling simulation of microdosimetry at component level
• Search for physical mechanisms
 Subsequently use for in-space predictions.
 Understand at which level ground based testing is space
representative
 Improve test methods
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Basic Mechanisms
• Metal : me,h ~105m2V-1s-1
m ~105m2V-1s-1
- negligible
• Oxide : me ~
-
me ~10-3m2V-1s-1
mh <10-5m2V-1s-1
Ionization
10-3m2V-1
s-1
mh ~ 10-5m2V-1s-1
Long-lived cumulative
m ~101m2V-1s-1
• Semiconductor : me ~
me,h ~ 101m2V-1s-1
10-3m2V-1s-1
-
Transient : Charge collection in the circuit
- Memory cell upset, latch-up, burn
Displacement
•
•
Drift:
Diffusion:
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t~0.5ns
t>0.5ns
Ji= q ni mi E + q Di grad(ni);
drift
diffusion
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i=e,h
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Geometrical effects
Musseau, 1994
•
Perturbation of several structures in a device by a unique ion
•
Charge collected by parasitic structures
Three Types :
1.
Shunt effect: The ion crosses several depleted regions. E.g ion
normally to n+pnn+ structrue
2.
Grazing angle: (75-90º) may cross
different sensitive areas
3.
Multiple Bit Upset: limited funnelled
charge collection by charge already
stored in the diode
->charge diffused in several neighbour
junctions
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SEE in complex devices
•
Complex devices: very large no of
individual transistors: principal and
parasitic
The effect of transients depends on:
•
Duration of the pulse compared to device
response time
•
Noise margins of the electrical node
•
Total charge of the transient
Characterisation of Sensitivity


•
# events( E  Ec )
2
Threshold (critical charge) & Sensitive ( LET , E ) cm / device 
( LET , E ) particle / cm 2  cos 
volume
•
Cross Section (sensitive area)

E max
Degradatio n Rate 

E min
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 (E) 

d
dE
dE
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CODES:
Structure
The framework
Radiation Input
• 2 approaches
–Statistic
–Microscopic
Sensitive Volume-FIT
•
•
•
•
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Validation
•Experimental data
•Other software
Iterative process:
3 modules:
Geometry Description,
Efficiency Matrix,
Analysis Module.
GEANT 4
Analysis
 calculates the SV shape that gives a best agreement with exp data
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SEE Monitors on PROBA II
• Aim
•
Technology Demonstration Module (TDM) integrated into the PROBA-II
satellite, was launched Nov 2009, into a 800 km polar orbit. This
experiment in support of in-orbit performance of modern memories aims
at providing SEU/SEL data as inputs to improved ground modeling,
predictions and testing.
SRAMs Selected for PROBA-II TDM Flight Experiment
Heavy Ion SEL Results RADEF (JYF0802).
Cross Section - (cm2/Device)
1.0E+00
1.0E-01
1.0E-02
1.0E-03
1.0E-04
Flight Lot 40°C #F1/#F2 - ISSI IS61
1.0E-05
Flight Lot 40°C #F1/#F2 - ISSI IS62
Flight Lot 40°C #F1/#F2 - Alliance AS7C
1.0E-06
Flight Lot 40°C #F1/#F2 - Samsung K6R
1.0E-07
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0
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Ion LET - MeV/(mg/cm )
30
35
8
40
From Bethe-Block to Space
• Main challenge for new trend technology
• Very different Sensitivities
• Particle momentum differences between ground based test data
and space radiation
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Conclusions & Further Work
Main topics
•
•
•
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Radiation damage is still a very shadowed road to explore
Many of the engineering analysis approaches are nowadays requiring
physical interpretation and improvement
We develop detailed tools, studies and physics simulation in order to
better understand and improve the analysis
Importance of ground based testing with ion beams.
Further work
•
Proceed with the dEdx vs bg analysis of ion beams experimental analysis
•
Increase the experimental database with testing at different energies,
High and low energies
Analyse in-flight data and correlate with ground based predictions
(testing and simulation)
•
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SV-FIT fundamentals
• Modular iterative tool
• Microdosimetry Monte-Carlo technique
• Device sensitive volume: charge deposited contributes entirely to
prompt charge collection.
N
• Input parameters:
Ne
– Ion cocktails description
Si
– Irradiation test data
• SEU threshold definition
Kr
• SV shape modulation
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Ar
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