1 risk analysis for improving production ramp-up bassetto 1, mili 1, siadat 2, tollenaere 1 2 1
TRANSCRIPT
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Risk analysis for improving production ramp-up
Bassetto1, Mili1, Siadat2, Tollenaere1
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Outline
Industrial context and question
Enterprise risk audit – practices analyses
Proposition & on going subject
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Industrial context of this research
• In semiconductor industry: ‘FE techno’– One new product generation: a technology– 2 years of development (Engineering)– 30 Development engineers– 1 techno 1B€– Commercial windows : From 2 to 5 years
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technological context
• From 120nm To 32nm techno Master 1,2nm +/- Å, Metrology tools @ 0,1 Å!
• Billion of times / wafer & 2.103 to 4.103 w/w
1,2nm +/- Å >1E10 times
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Number > 107/chip
Number > 103C/Wafer
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Industrial context
• Over 400 Process Operations
• Around 2 months to 1 full wafer
• 1 Fab Over than 40K Control Charts
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Industrial context
[Benfer, 96]I
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Semiconductor industries
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industrialization
Production size
Launch, 1 year
Maturation 1 year
Production, 2 years
Stop, 3 years
Time
YieldProduction volume max
100 %
Stakes
Launch Maturation Production Transfert and stop
Production life cycle in Semiconductor industries
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Learning Curves – eg on quality
• Several scenarios for quality managment:WIP
NC
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WIP
NC
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WIP
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WIP
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Case 1Case 2
Case 3 Case 4
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Research quest:
How being systematically in the case 3 or better ?
Before the ramp-up, risks are potentials (being known or not). During it, they become real events and reduce performance.
How prevent and mitigating them in a reliable manner?
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Outline
Industrial context and question
Enterprise risk audit – practices analyses
Proposition & on going subject
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Enterprise Description
• A best in class manufacture– ISO/TS – ISO 14001– Non conformity Mgt, Customer Claims,
Preventative & Predictive maintenance, Powerfull Process control, effective FMEA, Functional & Used Electronic Documentation, a cuting edge R&D…
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Risk management status
• Risk management methods & tools are not connected
FAB IN PROCESS
Reading sens
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Maintenance Issue
Change
8DRisk analysis
FMEAQuality
analysis
New Technology Introduction
Eg Analysis
FMEAActions & Controls
Quality analysisActions & Controls
Eg AnalysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
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Risk management status
• What happened when IS are not connected…
Eg. 2
Risk analysis
8D
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Change
Quality analysis
Quality analysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
FAB IN PROCESS
Reading sens
Maintenance Issue
FMEA
New Technology Introduction
Eg Analysis
FMEAActions & Controls
Eg AnalysisActions & Controls
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• Experts are thinking that
Extract from the Preliminary analysis of a tool
1 occurrence MAX each an !
The lack of links between risk management processes (1/2)
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• Facts Underline an other reality for the « Wafer aligner » element
3 occurrences over 13 weeks 12 per year: If FMEA have been updated RPN ranking
grow up from 10 to 25
‘OCC’ will pass from 2 to 5
The lack of links between risk management processes (2/2)
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Risk management status
• Risk management not uniform
FAB IN PROCESS
Reading sens
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Maintenance Issue
Change
8DRisk analysis
FMEAQuality
analysis
New Technology Introduction
Eg Analysis
FMEAActions & Controls
Quality analysisActions & Controls
Eg AnalysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
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S Action plan coherency ?
Risked zone of the process ?
Coherency on ctrls ?
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Outline
Industrial context and question
Enterprise risk audit – practices analyses
Proposition & on going subject
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Risk management status
• Risk management not uniform
FAB IN PROCESS
Reading sens
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Maintenance Issue
Change
8DRisk analysis
FMEAQuality analysis
New Technology Introduction
Eg Analysis
FMEAActions & Controls
Quality analysisActions & Controls
Eg AnalysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
Action plan & Controls
Risk Analysis
FAB IN PROCESS
Reading sens
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Maintenance Issue
Change
8DRisk analysis
FMEA
Quality analysis
New Technology Introduction Eng Analysis
FMEAActions & Controls
Quality analysisActions & Controls
Eg AnalysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
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Risk management proposition
• Need of information update => info reliability
UpdateFAB IN PROCESS
FAB EVENTS : * Non conformities* Customr claims* Process ctrl issue* Maintenance issue* Change…
Risk analysis
Action plan
Control Plan
Risk documents
-FMEA-update
Applies on
control
Information on risks
Reading sens
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• Toward a more « rational » organization15000 Risks analysed in 3 main organizations,
involving more than 600 Engineers
Passed 5 customers Audit with success
Updates are performed:
1) Automatically for process NC,
2) Automatically unsched event on tool
3) Manually for Scraps (After team problem solving close its actions)
Results (1/3)
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Reusing risks analysis for technology assessment
• One central risk database for every technology developement.
Launch Maturation Production Stop
Launch Maturation Production Stop
Technology n life cycle
Launch Maturation Production Stop
Technology n+2 life cycle
Launch Maturation Production Stop
Technology n+1 life cycle
Risk DataBase
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4) Reusing risk analyses for technology assessement
• Already used for CMOS120, CMOS90, CMOS 65 ramp-up and reliability analysis
Launch Maturation Production Stop
Launch Maturation Production Stop
Technology n life cycle
Launch Maturation Production Stop
Technology n+2 life cycle
Launch Maturation Production Stop
Technology n+1 life cycle
Risk DataBase
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• More than 1 year of Yield data
Impact on operations scraps
80
82
84
86
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90
92
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96
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100
1 2 3 4 5 6 7 8 9 10 11 12
improvement
Still massive scraps
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• Local improvement: Organizational improvement satisfactory
– Customer feedback very positive– Learning on going: ROI achieved @ the first lot
saved !
• Global plant improvement: Learning curve still NOT satisfactory
– Confidence in analyses can theorically be improved however many difficulties are encountered. (HR issues also to reduce fire fighting)
Results (3/3) - summary
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Outline
Industrial context and question
Enterprise risk audit – practices analyses
Proposition & on going subject
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Main issue for linking risks and manufacturing ctrl plan
One new central question: how to get process model?
• What is f ?
Process
Measured Inputs: I
(Prod operation)
Measured Outputs: O
(Product parameters)
Measured Internal Variables: V
(control parameters)O = f(I,V)
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Thank you for the audience
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2) How to get more robust control plans ?
How to find holes in the ctrl plan ? Links between risks analyses and control plans
R2R
FDC
SPC
PT
EWS
Visu
Tool Alarm- Maintenance
CustomerNon Conformity
Impacting events
Levels of controls
Visual inspection détection
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3) Update loop improvement (1/2)
• How to get the loop more effective ?
legend
Pg: Production
System
Pd : Detection
Pa : Analyse
Pap: Perform Action plan
Risk DataBase
Impact
E (Eg, Ef, Ed)
Eg*Ef
Ap (Ag, Af, Ad)
Ed (Eg, Ef, Ed)
> update
<help in the analysis
A (Ag, Af, Ad)
Objects
Activity
Pa : probability that this activity
happens
{R} ={ R / R=(Rgi, Rfi, Rdi, Vi : confidence in
the analysis)}
1 PhD StudentAymen MILI
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3) Update loop improvement (2/2)
• How to get the loop more effective ?
Pg: Production
System
Pd : Detection
Pa : Analyse
Pap: Perform Action plan
Risk DataBase
Impact
E (Eg, Ef, Ed)
Eg*Ef
Ap (Ag, Af, Ad)
Ed (Eg, Ef, Ed)
A (Ag, Af, Ad)
{R} ={ R / R=(Rgi, Rfi, Rdi, Vi : confidence in
the analysis)}
1 PhD StudentAymen MILI
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Risk management processes audit (1/3) @ STMicroelectronics
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Risk management processes audit (2/3) @ STMicroelectronics
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Risk management processes audit (3/3) @ STMicroelectronics
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• 5 procedures of risks managment held by 5 different organizations
• All these procedures are isolated from each others
Audit Conclusions @ STmicro.
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• A more realistic scenario:
WIP
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Case 5
2) LESS VARIATIONS1) NO SLOPE
Learning Curves – eg on quality
WANTED ON NC :
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• Production point of view• ∞ failure modes number :• Failure modes come from a preliminary risk analysis
(PRA)
Actual risk
Potential Cause/ Mechanism of Failure
OCC
N°
Item/Function Potential Failure Mode Potential Effects of
Failure Recommended Actions
Current Controls Prevention
Current Controls Detection
DET
RPN
SEV
CLASS
Risk actions
Prod operation
Thickness too low
Yield loss Equipment drift
2 SPC, PT Parameter
PM
FDC on tool
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All steps Defectivity
Residues and/or particles affecting via or line continuity--> Yield loss
6 RF 4Bi-weekly monitoring
In-line defectivity after every CMP level (line continuityES25 inspection after M2 CMP (via continuity)
4 96
All steps Defectivity
Residues and/or particles affecting via or line continuity--> Yield loss
6 Temperature 2Bi-weekly monitoring
In-line defectivity after every CMP level (line continuityES25 inspection after M2 CMP (via continuity)
4 48
All steps UnderetchVia resistance OOSYield loss
6 C
Metalic contamination due to gasket corrosion 4 None 8 192
1/ Gasket wo Nickel2/ APC implemented
All steps UnderetchVia resistance OOSYield loss
6
Metalic contamination due to gasket corrosion 2
Gasket without Nickel
1/ Gasket wo Nickel2/ APC implemented 6 72
FDC to be implemented on lot
FMEAFMEA
1) The point of view vs risk analysis
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SPC approach in the FMEA template
• The process control Point Of View• For 1 item function: 3 associated failure modes:
– Variable too low
– Variable too high
– Variable gradien (temporal or surfacic) Toward an AUTOMATIC RISK ANALYSIS UPDATE
Actual risk
Potential Cause/ Mechanism of Failure
OCC
N°
Item/Function Potential Failure Mode Potential Effects of
Failure Recommended Actions
Current Controls Prevention
Current Controls Detection
DET
RPN
SEV
CLASS
Risk actions
PT Variable to control
OOC Product impact, increase scrap rate
7 Tbd ?
Cpk V
alue
TBD PT 6
1) The point of view vs risk analysis
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Main issue for linking risks and manufacturing ctrl plan
1) Analysis is not performed2) Link does not exist between product FMEA and
product control plan
SEV
OCC
DET
RPN
Actual risk
Potential Cause/ Mechanism of Failure
OCC
N°
Item/Function Potential Failure Mode Potential Effects of
Failure Recommended Actions
Responsible & Target
Completion Date
Forcasted
Current Controls Prevention
Current Controls Detection
DET
RPN
SEV
CLASS
Risk actions
Prod operation Thickness too low
Yield loss Equipment drift
2 SPC, PT Parameter
PM
FDC on tool
16 12
SEV
OCC
DET
RPN
Actual risk
Potential Cause/ Mechanism of Failure
OCC
N°
Item/Function Potential Failure Mode Potential Effects of
Failure Recommended Actions
Responsible & Target
Completion Date
Forcasted
Current Controls Prevention
Current Controls Detection
DET
RPN
SEV
CLASS
Risk actions
PT Variable to control
OOC Product impact, increase scrap rate
7 Tbd ?
Cpk V
alue
TBD PT 6
Are our control plan coherent toward customers needs ?
1) The point of view vs risk analysis
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Risk management status
• What happened when SI are not connected
– Every change impact, difficult to evaluate
– Multiplicaiton of way to control the process and stop the process
– No clear vision of control efficiency• It is not necessary to add cameras
on highways to reduce speed if deadly accidents are in national roads !
– Multiplication of action plan => dispersion of working teams
– Multiplication of SI to analyse the process
– Control is no more a question of facts but people lobbying
FAB IN PROCESS
Reading sens
Non conformities
Scrap
Customer reclaim
Process Ctrl Issue
Maintenance Issue
Change
8DRisk analysis
FMEAQuality analysis
New Technology Introduction
Eg Analysis
FMEAActions & Controls
Quality analysisActions & Controls
Eg AnalysisActions & Controls
Risk Analysis Actions &Controls
8D Actions & Controls
R2R
FDC
SPC
PT
EWS
Visu
Tool Alarm- Maintenance
CustomerNon Conformity
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