1. NOBUGS conference 11-05-2002 Camera “Scanning Probe Microscope” software for instrument control and data analysis. E.H. v. Tol – Homan, G. v. Velzen, R. v. Gastel, M. Seynen* University Leiden, The Netherlands *Institute for Atomic and Molecular Physics (AMOLF-FOM), Amsterdam http://www.physics.leidenuniv.nl/sections/cm/ip/11-05-2002

2. Overview  Introduction to Scanning Probe Microscopes (SPM)  SPM – software specifications (video rate)  Instrument control  Data analysis  SPM – software architecture  Conclusion

3. Scanning Probe Microscopes (SPM) Scanning Probe Microscopes: Scanning Tunneling Microscope (STM) Atomic Force Microscopes (AFM) …

4. Scanning Probe Microscopes (SPM) Scanning Probe Microscopes: Scanning Tunneling Microscope (STM) Atomic Force Microscopes (AFM) … The Scanning Tunneling Microscope works like a record player…

5. Scanning Probe Microscopes (SPM) X,Y Scan circuit Piezo Feedback Electronics PC specimen U sample Z It tip

6. Scanning Probe Microscopes (SPM) Line scan image of graphite surface. Each bump corresponds to a single carbon atom. The size of the image is only 3 nm  3 nm. 15 years Ago: Now: Perspective color view of Graphite surface “Photo Camera”

7. Scanning Probe Microscopes (SPM) New “Video camera” High speed scanning probe microscope: 25 pictures (256 x 256) per second Maximum scan speed: 3,3*10 6 pixels/sec

8. Scanning Probe Microscopes (SPM) Au (110) Usample =-0.7V ~ 22000 pixels/sec 300 nm x 300 nm

9. Scanning Probe Microscopes (SPM) Au (110) Usample =-0.7V ~ 134000 pixels/sec 300 nm x 300 nm

10. SPM – software specifications Computer specification for a high speed SPM:  Dual processor: first processor:data display / analysis / scaling second processor:instrument control  Dual monitor: first monitordata display second monitorinstrument control - window

11. SPM – software specifications General specifications for a high speed SPM: 1.Two “user modes of operation”: online and offline mode. Online Mode -measurement -analysis Offline Mode -Post measurement analysis GUI

12. SPM – software specifications Online ModeOffline Mode GUI General specifications: 2.The program uses a DLL to configure and drive the hardware of the SPM. (Different DLL’s for each SPM) STM- DLL…AFM- DLL

13. SPM – software specifications Boundary requirements:  Very stable and reliable  Fast data handling and graphics  Extendable, Users can add own filters  Windows look and feel  RECOVERY PROCEDURE !

14. SPM – software specifications Why winNT (decided three years ago) ?  Multi tasking operating system  Drivers for microEnable / hotlink only available under winNT.  Commonly know environment  Offline mode can run under windows 98,2002, XP RT/Time-sharing  Real-time part: dedicated hardware  Time sharing – part: winNT (GUI).

15. SPM – software specifications A collection of C++ classes and an application framework for creating Microsoft windows-based applications. Document / View structure

16. SPM – software specifications Document / View structure: SPM – DATA

17. Instrument control GUI Online Mode -measurement -analysis Offline Mode -Post measurement analysis

18. Instrument control MAIN SPM DLL Data display Instrument control

20. Measurement mode: 1. Approach (bringing the tip to the surface) 2. Setting scanning parameters 3. Scan (with video rate) 4. Save During measurement analysis and display through main program.

21. Data analysis GUI Online Mode -measurement -analysis Offline Mode -Post measurement analysis

23. Data analysis

24. Height line:

25. Data analysis 3D:

26. Data analysis Filter functions:  Clipping: image size adjust  Filters:  Differentiate,  Background subtraction  … FILTER DLL MAIN USER DEFINED DLL

27. Data analysis Original data:

28. Data analysis Background subtraction:

29. Data analysis Differentiate (line by line) data:

30. SPM – software architecture Architecture Online ModuleOffline Module GUI STM- DLLAFM- DLL

31. SPM – software architecture The interface (for Instrument Control) DLL:  MFC DLL, dynamically linked to the MFC-libraries.  Init Instance / Exit instance are called when the DLL is loaded / freed from memory.

32. SPM – software internally MAIN DLL SendSPMCommand This function is defined in the DLL, and called by the MAIN. SendNotify This function is defined in the MAIN, and called by the DLL.

33. SPM – software internally MAIN DLL SendSPMCommand This function is defined in the DLL, and called by the MAIN. Set / GetDeviceConfig GetDeviceStatus / GetLastError CommandWindowCreate / Close …

34. SPM – software internally MAIN DLL SendNotify This function is defined in the MAIN, and called by the DLL. StartScanMeasurement UpdateFrameData StopScanMeasurement …

35. SPM – software internally Threads overview MEASUREMENT GUI DISPLAY Thread Safe

36. SPM – software internally DLL Hardware Message Loop Disk

37. SPM – software internally Message Loop MAIN ProcessFilters

38. Conclusion A graphical user interface for a high speed SPM (with video rate) has been developed using MFC and winNT. NO BUGS

39. Interface physics group The Team: Prof. Dr. J.W.M. Frenken (Group leader) Dr. ir. T.H. Oosterkamp (Group leader) Dr. M.J. Rost (Post-Doc) Ir. K. Schoots (Ph.D. Student) R. v. Gastel (Ph.D. Student) Ing. B. Crama (Electronics)*B. Okhuysen (Group leader) Ing. P. Schakel (Electronics) *Ing. M. Seynen (Software) Ing. E.H. v. Tol-Homan (Software)*Ing. H. Dekker (Electronics) Ing. G. v. Velzen (Software)*Ing. A. Vijftigschild (Electronics) *AMOLF/FOM Email: vantol@fwneld.leidenuniv.nl Web page: http://www.physics.leidenuniv.nl/sections/cm/ip/