380 likes | 676 Views
A Shimadzu Group Company. 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. Distribution of XPS instruments. 56% Industrial 44% Academic. A Shimadzu Group Company. What are we missing out on?.
E N D
A Shimadzu Group Company 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 Distribution of XPS instruments 56% Industrial 44% Academic
A Shimadzu Group Company What are we missing out on? • Sate of the art instruments offer: • Improved sensitivity • improved detection limits • reduced acquisition time • Smaller spot sizes • ~ 5m spot size available • XPS imaging • 3 m spatial resolution
A Shimadzu Group Company 3 decades of improvement Ag 3d5/2 FWHM Mono 0.6eV Mg 1.0eV
A Shimadzu Group Company 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 -CP process PDMS stamp alkyl amine PE-COOCOR Oxidised PE substrate Unpassivated region Passivated layer PE-COOCOR i) PTBA ii) MeSO3H PE-COOCOR hyperbranched PAA film alkyl amine
A Shimadzu Group Company PAA on Au films Au 4f photoelectron image attenuation of Au substrate gives contrast mechanism PAA layer Au substrate alkyl amine
A Shimadzu Group Company C 1s - 27 m analysis area C 1s from PAA layer PAA
A Shimadzu Group Company Au 4f & C 1s image
A Shimadzu Group Company < 3m spatial resolution
A Shimadzu Group Company Fluorinated PAA on PE Experiment repeated using PE substrate with PAA layer being fluorinated PE-COOCOR
A Shimadzu Group Company C 1s spectra
A Shimadzu Group Company 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 O1s images variable FOV
A Shimadzu Group Company 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 C1s chemical state image
A Shimadzu Group Company 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 In 3d quantification In 3d3/2 used for quantification Overlap with Ca 2s
A Shimadzu Group Company Corrosion tests • Cut anode surface used to represent bulk • XPS In 0.02wt% • GDOES In 0.0185wt% • As cast anode surface ~1wt% In • Corrosion tests show an increase to 4wt% over 1 years simulated corrosion
A Shimadzu Group Company In & Fe conc versus dissolution time
A Shimadzu Group Company 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 Optical image contact pad
A Shimadzu Group Company Wide scan - low concentrations O 1s 7.53% C 1s 37.0% Au 4f 54.42% Co 2p 0.78% Ni 2p 0.27%
Co 2p3/2 Ni 2p3/2 Co metal Co oxide A Shimadzu Group Company High resolution Co2p and Ni 2p
A Shimadzu Group Company Polymer reflector contamination Cross section through a “dimple” PP contamination ca. 500 mm
A Shimadzu Group Company Wide scan from 700m area
A Shimadzu Group Company VB from 700m area
A Shimadzu Group Company Valence band of PE & PP
A Shimadzu Group Company 110m spot size C 1s
A Shimadzu Group Company 110m spot size VB VB in flat VB in hole PP character VB
A Shimadzu Group Company Bond pad contamination Optical image of Al pads in-situ Al 2p photoelectron image l
A Shimadzu Group Company 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 Al 2p and F 1s images F 1s image shows distribution of F on pads
A Shimadzu Group Company Small spot spectroscopy 55um spectra show Al/F on pad
A Shimadzu Group Company Photoelectron images F 1s and al 2p images shwo distribution of F across bond pad
A Shimadzu Group Company 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 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