1. The STATE of the art - XPS Dr Chris Blomfield Dr Adam Roberts, Dr Simon Hutton Kratos Analytical Ltd www.kratos.com A Shimadzu Group Company

2. Distribution of XPS instruments A Shimadzu Group Company 56% Industrial 44% Academic

3. What are we missing out on? Sate of the art instruments offer: –Improved sensitivity improved detection limits reduced acquisition time –Smaller spot sizes ~ 5  m spot size available –XPS imaging 3  m spatial resolution A Shimadzu Group Company

4. 3 decades of improvement A Shimadzu Group Company Ag 3d 5/2 FWHM Mono0.6eV Mg1.0eV

5. Applications to  -CP Patterning of polymer substrate (polyethylene PE) with poly(acrylic) acid PAA. –PAA impermeable, wet and dry etch resist –PAA films easily functionalised –capped with PEG can be used for bio-applications cell growth Oxidised PE film is prepared PDMS stamp (optical mask) prepared with n-alkylamine PE “stamped” with amine to passivate PE Unpassivated regions react with PTBA Hydrolysis of this layer leads to PAA A Shimadzu Group Company

6.  -CP process PE-COOCOR i) PTBA ii) MeSO 3 H alkyl amine hyperbranched PAA film PDMS stamp Oxidised PE substrate A Shimadzu Group Company alkyl amine Passivated layer Unpassivated region

7. PAA on Au films Au 4f photoelectron image attenuation of Au substrate gives contrast mechanism Au substrate PAA layer alkyl amine A Shimadzu Group Company

8. C 1s - 27  m analysis area PAA C 1s from PAA layer A Shimadzu Group Company

9. Au 4f & C 1s image A Shimadzu Group Company

10. < 3  m spatial resolution

11. Fluorinated PAA on PE PE-COOCOR A Shimadzu Group Company Experiment repeated using PE substrate with PAA layer being fluorinated

12. C 1s spectra A Shimadzu Group Company

13. Adhesive coverage on paper Inhomogeneous paper sample with uneven coverage of adhesive - lead to adhesive failure Optically - sample was homogenous - white XPS O1s image clearly identifies adhesive distribution A Shimadzu Group Company

14. O1s images variable FOV

15. Chemical state images C1s image allows investigation of chemistry –small spot analysis shows variation in C-H and C-O Energy resolution of SMA allows chemical imaging of different C 1s species A Shimadzu Group Company

16. C1s chemical state image A Shimadzu Group Company

17. Indium in commercial Al-Zn-In sacrificial anode Improved detection limits<0.05% allow analysis of low concentrations of elements –Al-Zn-In anodes are used to protect marine steel structures from corrosion. –study with XPS of the active In element –reveals surface segregation to a maximum of 4% over 1 year exposure A Shimadzu Group Company

18. In 3d quantification Overlap with Ca 2s In 3d 3/2 used for quantification A Shimadzu Group Company

19. Corrosion tests Cut anode surface used to represent bulk –XPS In0.02wt% –GDOESIn0.0185wt% As cast anode surface ~1wt% In Corrosion tests show an increase to 4wt% over 1 years simulated corrosion A Shimadzu Group Company

20. In & Fe conc versus dissolution time A Shimadzu Group Company

21. Summary In is surface segregated to Anode surface compared to the bulk - inverse segregation In is believed to segregate to the metal:oxide interface a more active surface Shows the activity of the anode is a surface phenomena - possible to investigate with improved detection limits A Shimadzu Group Company

22. Optical image contact pad A Shimadzu Group Company

23. Wide scan - low concentrations O 1s7.53% C 1s37.0% Au 4f54.42% Co 2p0.78% Ni 2p0.27% A Shimadzu Group Company

24. High resolution Co2p and Ni 2p Co 2p 3/2 Ni 2p 3/2 Co oxide Co metal A Shimadzu Group Company

25. Polymer reflector contamination ca. 500  m Cross section through a “dimple” PP contamination A Shimadzu Group Company

26. Wide scan from 700  m area A Shimadzu Group Company

27. VB from 700  m area A Shimadzu Group Company

28. Valence band of PE & PP A Shimadzu Group Company

29. 110  m spot size C 1s A Shimadzu Group Company

30. 110  m spot size VB A Shimadzu Group Company VB in flat VB in hole PP character VB

31. Bond pad contamination A Shimadzu Group Company l Al 2p photoelectron image Optical image of Al pads in-situ

32. Bond pad contamination Bad adhesion was observed in Al bond pads Optical images was used to identify area of know failure XPS images and small spot show F contamination Distribution of F indicates residue from plasma etching step in production A Shimadzu Group Company

33. Al 2p and F 1s images A Shimadzu Group Company F 1s image shows distribution of F on pads

34. Small spot spectroscopy A Shimadzu Group Company 55um spectra show Al/F on pad

35. Photoelectron images A Shimadzu Group Company F 1s and al 2p images shwo distribution of F across bond pad

36. Summary Modern XPS instruments are very powerful analytical tools As well as improved automation, reliability and accuracy: –imaging, detection limits, resolution,  - probe..... How to get more instruments into UK???? A Shimadzu Group Company

37. Acknowledgements  -CP Richard Crooks Texas A & M University In anode John Norris & Morgan Alexander. CPC, UMIST, UK Polymer VB Gary Korba 3M Central Research Labs Minneapolis Paper sample James Tse Avery Dennison Pasedena. USA A Shimadzu Group Company