1 Risk analysis for improving production ramp-up Bassetto 1, Mili 1, Siadat 2, Tollenaere 1 2 1

2 Outline Industrial context and question Enterprise risk audit – practices analyses Proposition & on going subject IEPIEP

3 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 IEPIEP

4 technological context From 120nm To 32nm techno  Master 1,2nm +/- Å, Metrology 0,1 Å! Billion of times / wafer & to w/w 1,2nm +/- Å  >1 E 10 times IEPIEP Number > 10 7 /chip Number > 10 3 C/Wafer

5 Industrial context Over 400 Process Operations Around 2 months to 1 full wafer 1 Fab  Over than 40K Control Charts IEPIEP

6 Industrial context [Benfer, 96] IEPIEP Semiconductor industries

7 industrialization Production size Launch, 1 year Maturation 1 year Production, 2 years Stop, 3 years Time Yield Production volume max 100 % Stakes Launch Maturation ProductionTransfert and stop Production life cycle in Semiconductor industries IEPIEP

8 Learning Curves – eg on quality Several scenarios for quality managment: WIP NC t volume WIP NC t volume WIP NC t volume WIP NC t volume Case 1 Case 2 Case 3 Case 4 IEPIEP

9 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? IEPIEP

10 Outline Industrial context and question Enterprise risk audit – practices analyses Proposition & on going subject IEPIEP

11 Enterprise Description A best in class manufacture –ISO/TS –ISO –Non conformity Mgt, Customer Claims, Preventative & Predictive maintenance, Powerfull Process control, effective FMEA, Functional & Used Electronic Documentation, a cuting edge R&D… IEPIEP

12 Risk management status Risk management methods & tools are not connected IEPIEP

13 Risk management status What happened when IS are not connected… Eg. 2 IEPIEP

14 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) IEPIEP

15 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) IEPIEP

16 Risk management status Risk management not uniform WLESWLES LESLES Action plan coherency ? Risked zone of the process ? Coherency on ctrls ?

17 Outline Industrial context and question Enterprise risk audit – practices analyses Proposition & on going subject IEPIEP

18 Risk management status Risk management not uniform IEPIEP

19 Risk management proposition Need of information update =>  info reliability IEPIEP

20 Toward a more « rational » organization 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) IEPIEP

21 Reusing risks analysis for technology assessment One central risk database for every technology developement. IEPIEP

22 4) Reusing risk analyses for technology assessement Already used for CMOS120, CMOS90, CMOS 65 ramp-up and reliability analysis IEPIEP

23 More than 1 year of Yield data Impact on operations scraps improvement Still massive scraps IEPIEP

24 Local improvement: Organizational improvement satisfactory –Customer feedback very positive –Learning on going: ROI 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 IEPIEP

25 Outline Industrial context and question Enterprise risk audit – practices analyses Proposition & on going subject IEPIEP

26 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) IEPIEP

27 Thank you for the audience

28 2) How to get more robust control plans ? How to find holes in the ctrl plan ?  Links between risks analyses and control plans Impacting events Levels of controls Visual inspection détection IEPIEP

29 3) Update loop improvement (1/2) How to get the loop more effective ? 1 PhD Student Aymen MILI IEPIEP

30 3) Update loop improvement (2/2) How to get the loop more effective ? 1 PhD Student Aymen MILI IEPIEP

31 Risk management processes audit STMicroelectronics IEPIEP

32 Risk management processes audit STMicroelectronics IEPIEP

33 Risk management processes audit STMicroelectronics IEPIEP

34 5 procedures of risks managment held by 5 different organizations All these procedures are isolated from each others Audit STmicro. IEPIEP

35 A more realistic scenario: WIP NC t volume Case 5 2) LESS VARIATIONS 1) NO SLOPE Learning Curves – eg on quality WANTED ON NC : IEPIEP

36 Production point of view ∞ failure modes number : Failure modes come from a preliminary risk analysis (PRA) Prod operation Thickness too low Yield lossEquipment drift 2 SPC, PT Parameter PM FDC on tool FMEA 1) The point of view vs risk analysis IEPIEP

37 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 PT Variable to control OOCProduct impact, increase scrap rate 7Tbd ? Cpk Value TBDPT 6 1) The point of view vs risk analysis IEPIEP

38 Main issue for linking risks and manufacturing ctrl plan 1)Analysis  is not performed 2)Link does not exist between product FMEA and product control plan   Are our control plan coherent toward customers needs ? 1) The point of view vs risk analysis IEPIEP

39 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 IEPIEP