Focused Ion Beam CENTRE INTERDISCIPLINAIRE DE MICROSCOPIE ELECTRONIQUE. Marco Cantoni, EPFL-CIME CIME ASSEMBLEE GENERALE 2007

Transcription

1 Focused Ion CENTRE INTERDISCIPLINAIRE DE MICROSCOPIE ELECTRONIQUE Present situation and vision Marco Cantoni, EPFL-CIME Dual Beam Nova 600 Nanolab from FEI Company FE-SEM & FIB: Ga LMIS 4 Gas Injector Systems Pt deposition (C9H16Pt) SiO2 deposition (TEOS) Insulator Enhanced Etch (XeF2) Selective Carbon Mill (MgSO4) Charge neutralizer system Omniprobe (in situ TEM lamella lift out) Fast Electron Beam Blanker (basic e beam lithography) As a part of the clean room facilities: in clean room environment. CIME: client of CMI with 1 main operator (technical personal), 1 PhD student access on a basis of 1-2 days per week Since April 2004: FIB at CMI EPFL 1

2 Applications Chip Modification Insertion of electrical connection: 1) Removal of isolating layer (milling) 2) Pt deposition (FIB deposition) M. Pavius CMI micro/nano-structuring at the CMI FIB-manufactured AFM-tips 2

3 in-situ lift-out TEM sample preparation of a Si nano-wire M. Pavius,, V. Pott, CMI TEM grid, 3mm diameter TEM, CIME M. Cantoni poly-silicon SiO 2 amorph Si 5nm 3

4 TEM sample preparation Prethinned sample preparation Prethinned sample on TEM-«grid» Rough milling at high currents filling of voids Nb 3 Sn superconductor P-Y. Pfyrter (diploma work) 4

5 2 windows method DF-STEM TEM lamellae preparation by FIB Focused Ion Beam adds a new dimension to TEM specimen preparation But: But: Take Takecare of of artifacts!!!!!! Large flat areas with uniform thickness (50-80 nm) Preparation of heterogeneous samples with difficult material combinations becomes possible Precise selection of the lamella position possible (devices) 5

6 CMI vision: FIB at CIME FIB: indispensable tool for a modern (leading) electron microscopy centre TEM lamellae preparation (50-60%) TEM specimen preparation for analytical TEM and advanced TEM techniques Technical and methodical Research & Development.. TEM lamellae preparation and SEM/STEM (HAADF) + EDX analysis in one machine: increased spatial resolution (approaching TEM resolution) with the ease of use of a SEM. Cross-sectioning of heterogeneous samples, biological samples and soft matter which are not accessible by mechanical preparation methods (polishing or ultramicrotomy). New FIB/SEM techniques (40-50%) Analytical FIB/SEM: cross-sectioning + EDX (on-the-spot) the combination of FIB & analysis offers the great advantage to stay under vacuum in the same machine (oxidization of surface during transfer) 3D-reconstruction (tomography) in BSE mode (mass density contrast) or FIB mode (channeling contrast) of heterogeneous (or porous) samples (for example cement, composite materials, ceramics and polymers). 6

7 vision: FIB at CIME FIB: indispensable tool for a modern (leading) electron microscopy centre TEM lamellae preparation (50-60%) TEM specimen preparation for analytical TEM and advanced TEM techniques Technical and methodical Research & Development.. TEM lamellae preparation and SEM/STEM (HAADF) + EDX analysis in one machine: increased spatial resolution (approaching TEM resolution) with the ease of use of a SEM. Cross-sectioning of heterogeneous samples, biological samples and soft matter which are not accessible by mechanical preparation methods (polishing or ultramicrotomy). chip modification, circuit editing (semiconductor application) prototyping TEM TEM-lamellae for external use (service) No New FIB/SEM techniques (40-50%) Analytical FIB/SEM: cross-sectioning + EDX (on-the-spot) the combination of FIB & analysis offers the great advantage to stay under vacuum in the same machine (oxidization of surface during transfer) 3D-reconstruction (tomography) in BSE mode (mass density contrast) or FIB mode (channeling contrast) of heterogeneous (or porous) samples (for example cement, composite materials, ceramics and polymers). FIB Type: Two Beam Type System requirements e-beam: kV, low voltage compatible (< 1kV) for charging (biological, polymer) samples Ion Beam: 30kV with possibility to work below 5kV (reduction of amorphous layer thickness in TEM lamellae and/or cross-sections for subsequent EBSD Analysis). 1kV if possible. Options: EDX Analysis in FIB configuration Micromanipulators for in-situ TEM lamellae lift-out and handling STEM detector: multi-segment for high-angle annular dark-field (HAADF) or orientation dependent dark-field (ODDF). Software options for automated TEM preparations, cross-sectioning and tomography (unattended over-night use). EBSD for 3D grain orientation analysis (optional, ready for ). 7

8 Public call for offers together with ETHZ and PSI, WTO procedure Sept «the ultimate TEM-lamella» (state of the art June 2007) TEST FEI HELIOS Nanolab 600 low kv cleaning at 1kV 8

9 3D Microscopy Journal of Microscopy, Vol. 216, Pt 1 October 2004, pp FIB Nanotomography 9

10 Preparing for slicing the end Automated milling and imaging of 170 slices (10h) align and crop 10

11 3D volume rendering, reconstruction: Orthogonal slices Sagittal slice Coronal slice The choice of the right detector SE detector (TLD) BSE detector (TLD) Ion beam imaging (SE) Ion beam for slicing and imaging requires stage movement! 11

12 Problem of serial sectioning: 3D-reconstruction of disordered microstructures From: J.C.Russ, D 2D Volume fraction?? Nr of particles???? Shape?? DualBeam FIB-Nanotomography Z z-spacing 10 nm Z X Y Electron image: 5 nmresolution Y Stacks with x100 images z-spacing pixel resolution X ème Colloque SFµ Grenoble 2007 atelier FIB Voxel based data volume Reconstruction of microstructure directly in 3D 12

13 Drift XZ Drift XZ Voxel, Resolution,, Pixel size Drift XZ Drift: 1.5 µm in 6 hrs X (~ 250 nm / hours) Drift is often not constant! Z Drift XZ X ème Colloque SFµ Grenoble 2007 atelier FIB Drift correction: 1.2 Beam shift calibration (V/µm) Reference marks 1.4 Algorithms with pattern recognition Shift beam after each slice

14 Particle recognition: Edge detection in 3D, Watershed for separation Voxel: 75nm Cube: 40* 20* 15 µm Size, 3D-shape, geometrical relationships between particles Grain size fraction 3 Cube size: 23.5x19.2x9.5 µm / Voxel size: 29.69x37.67x60 nm / Nr. of particles: 2236 (total), 1404 (inside) Quantitative microstructure analysis Algorithms Münch and Holzer 2006 J.Amer.Ceram.Soc. FIB-nt of particulate systems part II: Object recognition and effect of boundary truncation 14

15 FIB-nt compared with other 3D-techniques New possibilities in 3D-microscopy: Combination of FIB-nt with Cryo, EDX, EBSD From: Uchic, Holzer and Inkson Mat. Res. Bul., subm. 15