BlankMap-World-noborders FYZIKA VE FIRMĚ Martin Zadražil, 9.11.2011 Forensic Applications in SEM : nGun shot residue analysis (GSR) nBullets and cartridge investigation nAfter car crash filament and bulb investigation nTool marks investigation nAnalysis of hairs, textiles and papers nPaints, prints and ink analysis nCounterfeit signatures, bank notes nMinerals, soils and metals analysis nand many others... SEM in Forensic Lab Silhouette_Target-1 Gunshot Residuum analysis. nIdentification of the shooter nAccording GSR particles on hands/clothes ™Typical size, shape ™Typical composition: Pb, Sb, Ba. Fig. GSR Particles composition in ternary chart GSR Analysis Value & Excellence in SEMs Electron Beam Lithography § Beam blanker electro-statically deflects the electron beam Beam interruption – Beam blanker 0 Value & Excellence in SEMs Technical details - Wide Field OpticsTM TESCAN TRACE GSR Hardware TESCAN TRACE GSR TESCAN TRACE GSR Hardware Integration path4127 TESCAN TRACE GSR Hardware TESCAN TRACE GSR n Powerful 50 MHz internal Pattern Generator n 2 x DAC for each stage of deflection coils (X, Y) n 16-bit scanning ramp DACs (65,536 x 65,536 virtual write field) n Variable dwell time n Static and dynamic distortion correction n Digital compensation of field errors n Automatic control of electrostatic beam blanker (10 MHz) Scanning Generator Synthetic YAG crystal nHigh efficiency – low noise nFast response nUnlimited lifetime nSuitable for high vacuum n Fig. On-line SE/BSE signal mixing Dwell/pix 1Mpix 100 fields analysis 50 us 50 s > 1 hour 100 ns 0.2 s < 3 min Fast detectors save time!! Fig. Everhart-Thornley SE Detector SE – Everhardt-Thornley type with YAG Fast imaging rate (20ns/pix) First Class Detectors BSE Detector Fig. Phase identification by material contrast Used for GSR particles location Tescan R-BSE detector Fig. Dependecy of BSE intensity on Atomic number Fig. Thresholding on a callibration sample Backscattered Electron Detector nCrucial for GSR applications nDetection of particles containing heavy elements Fast imaging rates, but no compromises on Image Quality Low-end solid-state BSE detector 1us/ pixel Middle-class scintillation BSE detector 500ns /pxl Latest generation Tescan YAG scintillation BSE 100ns /pxl Testing sample: Gold on Si imaging standard Other accessories EBIC, Absorbed current measurement, IR chamber view camera and many other EBSD TEI EDX/WDX CL SEI/BEI LVSTD Great Analytical Potential Great Analytical Potential Positioning Accuracy During GSR analysis the sample is divided into individual fields. Location and analysis of the particles is done filed-by-field using stage movements. Positioning accuracy is critical parameter for GSR analysis. Tescan XM Stage: XY Range : 130 x 130 mm Min. Step : 300 nm Relocation accuracy: < 2um guaranteed Speed: 5 mm/s Stage movements C:\Users\tescan\Documents\TESCAN\prezentace\fyzika ve firmě\source\TRACE\20positions.bmp Stage Positioning Accuracy Image montage from 1048 BSE image fields with two submicron GSR particles found from totaly 48 detected particles. Morphological Analysis TESCAN KOREA Users Meeting 2009, Hanyang University shapes01 shapes01-area shapes01-roundness Roundness: R2/(4*đ*Area) ■Circle = 1 ■Square = 1.3 ■Triangle = 1.5 ■Ellipse = 2 ■Dendrite ~ 15 ■Thread ~ 25 shapes01-compactness Extension: ■Circle = 0 ■Square = 0.3 ■Triangle = 0.5 ■Ellipse = 2.5 ■Dendrite ~ 4 ■Thread ~ 14 Classification by Area Classification by Roundness Classification by Extension (Compactness) nObject size and shape classification nOver 40 parameters n nObject filtering n nStatistical output TESCAN ENFSI Results TESCAN TRACE GSR TRACE GSR Results Plano GmbH TESCAN, a.s. 10/15/20 µm 3 3 0,5 µm 38 36 0,7 µm 30 29 1 µm 33 32 1,5 µm 32 30 2 µm 27 27 2,5 µm 27 27 total no. 190 185 summary1 TESCAN ENFSI Results TESCAN TRACE GSR C:\Users\tescan\Documents\TESCAN\prezentace\fyzika ve firmě\source\TRACE\spec.tif Particle 4 Nanotechnology Workbench FEG SEM FIB GIS EDS BSE EBSD SE Nanomanipulators E-Beam Blanker Fig. Tescan LYRA Demo as installed on EMC Aachen 2009 SEM objective lens FIB column nose GIS stage with nozzles What’s Inside? One Coincidence Point for All Parts Ion Beam Imaging nSE generated by ions nIon imaging resolution < 5 nm ✓High surface sensitivity with ions ✓High channeling effect contrast nIon imaging is destructive! n n nSE generated by electrons nHigh Electron Imaging Resolution nLower surface sensitivity especially for light elements ✓Nondestructive - reason for “dual beam” systems Pillar in silicon diameter 1μm SE imaging FIB p, SEMq Electron Beam Imaging Why SEM + FIB on One System? FIB + GIS Capabilities nEnhanced Milling (Etching) – examples: XeF2 enhances Si, SiO2 and W etching by factor of 5-100 times; H2O of PMMA and diamond 10-20 times nSelective Milling (Etching) – combination of enhanced and reduced milling. Examples: H2O greatly reduces etching of Al, Si and SiO2; XeF2 of Al. nMaterial deposition – Adsorption of the precursor molecules on the surface, ion beam (or e-beam) induced dissociation of the gas molecules, deposition of the material atoms (e.g. Pt, W, C, SiOx) . Gas Injection System Option Common SEM+FIB Applications nNano-structuring nIC process inspection and failure analysis nNano-tomography nLocal cross-sectioning, thin film thickness measurement nTEM sample preparation nBiology nMaterials science nMineralogy nFossils analysis nForensic applications Applications Forensic Application Gun Shot Residue Volume Analysis Simultaneous imaging of the milling process. Simulteneous Imaging Questions ? Value & Excellence in SEMs Applications Genesis spacecraft File:Genesis Sample Return Sticker.jpg The aim of the NASA’s Genesis sample-return mission was to collect solar wind, material ejected from the outer portion of the sun, and return it to Earth. Value & Excellence in SEMs Applications Collectors after assembly on earth before flight The collectors after assembly on Earth before flight This was done by allowing the species to implant in the surfaces of ultra-pure collectors. These collectors included single crystal, sapphire, silicon carbide; those materials coated with aluminum, silicon, diamond like carbon, and gold; and isotopically enriched polycrystalline diamond and amorphous carbon. The majority of these materials were distributed on five collector arrays. Three of the materials were housed in an electrostatic concentrator designed to increase the flux of low-mass ions. There was also a two-inch diameter bulk metallic glass collector and a gold foil, polished aluminum, and molybdenum coated platinum foil collector Value & Excellence in SEMs Applications Genesis Timeline Genesis Timeline Value & Excellence in SEMs Applications The Genesis mission was launched in August 2001. The spacecraft was sent to a special orbit 1 million km from Earth where it was well away from any contamination and exposed ultra-pure collectors to the solar wind. The Genesis mission returned to Earth on September 8, 2004 after a three-year mission. Value & Excellence in SEMs Applications Genesis entry phase graph artist renderings 8 artist renderings 8 The intent was to deploy a drogue chute high over the Utah desert and to catch the capsule in mid-air by helicopter. The capsule would then be opened in a cleanroom constructed for that purpose. Value & Excellence in SEMs Applications Although the mission was a success with solar wind atoms implanted into the collectors, the return to Earth was ‘non-optimal’ with the parachutes failing to open. Unfortunately, both chutes failed to deploy, causing the capsule to fall to the desert floor at a speed of 311 km/h. Value & Excellence in SEMs Applications Gravity switch After studying the problem for a month, the board announced the capsule had crashed because four tiny gravity switches that were supposed to release the parachutes were installed backward. Value & Excellence in SEMs Applications Monument Purchased and Designed by Genesis Team Members to Commemorate the Return to Earth Monument purchased and designed by Genesis team members to commemorate the return to Earth A minute’s of silence shall be observed….. Value & Excellence in SEMs Applications Photo of foils being removed from the SRC lid in the field. Hundreds of collector fragments were retrieved Photo of a gold foil collector Photo of foils being removed from the SRC lid in the field. Value & Excellence in SEMs Applications Sorting shards by material type. File:Genesis recovery 09.09.2004.jpg Genesis Array Removal from Canister Karen McNamara Assesses Canister Condition Backside of Collector Array in the UTTR Cleanroom Hours After Recovery Backside of Collector Array Collectors after assembly on earth before flight Gold Foil Post-landing Gold Foil Collector – post landing Value & Excellence in SEMs Applications Genesis Timeline Genesis Timeline http://www.ssl.berkeley.edu/graphics/diskBig.jpg Value & Excellence in SEMs Applications REQUIREMENT> SEM-EDS instrument with the ability to perform fast, automated detection, location and quantification of 10-μm clay-based dirt particles, molybdenum coating and platinum substrate over the entire area of minimum 16 cm x 16 cm square) crumpled Pt-Mo foils. Approximately 8000 cm2 Pt-Mo foils will be imaged in total. Gold Foil Post-landing http://www.ssl.berkeley.edu/graphics/diskBig.jpg Gold Foil Post-landing < Gold Foil Collector – post landing The large samples to be examined are foils (sheets) of Pt with a Mo coating. These foils were used in the Genesis spacecraft to collect solar wind particles; the particles are embedded in the Mo and Au layer. The foils were of course damaged during the crash of the Genesis capsule. (i) radioactive nuclides in the solar wind collected by the NASA Genesis mission; (ii) the study of cometary dust collected by the NASA Stardust mission, and (iii) the study of interstellar dust impacts in foils, also collected by the NASA Stardust mission. Value & Excellence in SEMs Applications C:\Users\tescan\Documents\DokumentyM\chamber genesis.png VEGA 3 XMU – X8M5 C:\Users\tescan\Documents\DokumentyM\komora genesis.png Design of the VEGA 3 XMU – X8M5 for the Genesis project Value & Excellence in SEMs Applications TESCAN's automated particle analysis The large samples to be examined are foils of Pt with a Mo coating. Particles are embedded in the Mo layer. The foils were of course damaged during the crash of the Genesis capsule