TECHNISCHE FAKULTÄT DER CHRISTIAN-ALBRECHTS-UNIVERSITÄT ZU KIEL

1. TECHNISCHE FAKULTÄT DERCHRISTIAN-ALBRECHTS-UNIVERSITÄTZU KIEL Not necessary but nice All comments will appear in this cloud ECS Hawaii 2008

2. In-Situ Assessment of Macropore Growthin Low-Doped n-Type Silicon  J. Carstensen, A. Cojocaru, M. Leisner, and H. Föll University Kiel; Germany What In-Situ Multi-Mode FFT Impedance Spectroscopy Can Do for You Good 1. Introduction 2. Persistent Pore Problems 3. Multi-Mode in-situ FFT IS 4. Theory and Results 5. Conclusions

3. In-Situ Assessment of Macropore Growthin Low-Doped n-Type Silicon  J. Carstensen, A. Cojocaru, M. Leisner, and H. Föll University Kiel; Germany What In-Situ Multi-Mode FFT Impedance Spectroscopy Can Do for You Not so good! 1. Introduction 2. Persistent Pore Problems 3. Multi-Mode in-situ FFT IS Note change in title! 4. Theory and Results 5. Conclusions

4. 1. Introduction “SCR theory”Lehmann Model 1990 Lehmann and Föll:Discovery of “n-macro(aqu, fsi) pores”(while trying to characterize solarSi) Good n-macro(fsi. aqu) “Pores” This picture started it all!

5. 1. Introduction “SCR theory”Lehmann Model 1990 Lehmann and Föll:Discovery of “n-macro(aqu, fsi) pores”(while trying to characterize solarSi) Not so good n-macro(fsi. aqu) “Pores” This picture started it all!

6. 1. Introduction Prediction: n-macro(aqu, bsi, litho) pores 1990 Lehmann and Föll:Discovery of “n-macro(aqu, fsi) pores” “SCR theory” Note trick with “veiled” text from before and full picture from before Lehmann modelworks !!! First SiMacropores

7. 1. Introduction Only up to a point 1990 Lehmann and Föll:Discovery of “n-macro(aqu, fsi) pores” “SCR theory” n-macro(aq, bsi) pores „Mode Transition“ Talk „Fast Pore Growth“ Talk Lehmann modelworks?? Lead up to the high point! 532 µm325 min

8. 1. Introduction Lehmann Model: Main parameter for pore growth is hole supply Limitations: Model does not address: Here going point by point makes sense- Leads up to major point at the end Chemistry: n-macro(org. electrolytes)n-macro(HAc. Electrolyte) Crystallography: <100> and <113> Pores “Curro” Pores Mode Transitions: Crysto - Curro transitionSelf-Organization: Diameter oscillationsCurrent response: Diameter, transitions Depth(t): Growth mode transitions

9. 1. Introduction Lehmann Model: Main parameter for pore growth is hole supply Limitations: Model does not address: Too much now, because you are spending time on each item. You will now loose your audience. They are all trying to figure out what all the text might mean. Chemistry: n-macro(org. electrolytes)n-macro(HAc. Electrolyte) Crystallography: <100> and <113> Pores “Curro” Pores Mode Transitions: Crysto - Curro transitionSelf-Organization: Diameter oscillationsCurrent response: Diameter, transitions Depth(t): Growth mode transitions

10. 2. The Problems Provoke! Provoke! Electrodes for Micro Fuel Cells Lead filaments Where are the promised products ? See how annoying these “moving-in” options are? Note change in color in the title part. Takes up the color from introduction. Not important, but helps to organize your thoughts. X-ray filter

11. 5. Conclusion • Multi-Mode in-situ FFT IS works • Modelling allows to extract a wealth of data relevant for pore growth • Scrutinizing and interpreting these data will lead to a better understanding of pore growth in semiconductors Conclusion = The Message!