Nova 200 NanoLab: SEM & EDS

Nova 200 Instrument Type Microscopy Techniques SEM, EDS Immersion Lens Imaging Staff Manager Alireza Ghaffari Staff Email alireza@caltech.edu Staff Phone 626-395-3984 Reserve time on FBS Request training via FBS User Dashboard Lab Location B203 Steele Lab Phone 626-395-1542 Manufacturer FEI (now Thermo Fisher) Model Nova 200 NanoLab

Description

The Nova 200 is the KNI's highest-resolution field-emission gun (FEG) analytical scanning electron microscope (SEM), equipped with an immersion lens for imaging sub-10 nm features and energy dispersive spectroscopy (EDS) for compositional analysis. It is also outfitted with a gallium focused ion beam (Ga-FIB) column, which is currently not operational because the Nova 600 NanoLab and ORION NanoFab together meet the KNI's Ga-FIB demand; Ga-FIB could be reactivated on the Nova 200 in the future. See a full list of training and educational resources for this instrument below.

SEM Applications

• Ultra-High-Resolution Imaging (Immersion Mode aka UHR Mode)
• High-Resolution Imaging (Field-Free Mode aka Normal Mode)
• Secondary Electron (SE) imaging with an Everhart-Thornley Detector (ETD) & Through-the-Lens Detector (TLD)
• Backscattered Electron (BSE) imaging with a TLD
• Tungsten deposition via Gas Injection System (GIS)
• Automated imaging with RunScript program & AutoScript language

EDS Applications

• Spectrum acquisition for qualitative and quantitative compositional analysis
• Linescan acquisition for 1D spatial compositional analysis
• Map acquisition for 2D spatial compositional analysis

Resources

SOPs & Manuals & SDS

• KNI Microscopy Policies
• Nova200 and EDS SOP, Manuals, SDS
• Nova NanoLab Operation Manual
• Bruker Quantax EDS Operation Manual
• Gas Injection Systems – Deposition of Tungsten (Technical Note)
• Gas Injection Systems – Delineation Etch for SiO₂ (Technical Note)
• Gas Injection Systems – Selective Carbon Etching (Technical Note)
• Scripting – AutoScript Language Manual (year 2000 Technical Note: most complete)
• Scripting – RunScript Manual

Video Tutorials

• Getting Started | Basic SEM Alignment
• Astigmatism Correction (Details | On Right-Angle Features | Stigmator Alignment)
• Adjusting TLD Voltage to Capture SE vs. BSE Signal
• Bruker EDS ESPRIT 2 Software (Overview | Basic Spectrum Collection and ID | Spectrum Acquisiton | AutoID Verification | Object Mode (Multi-Point Analysis) | Line Profile Analysis)

Graphical Handouts

• SEM & EDS/WDS Concepts
• SEM Alignments
• Guide to Optimizing SEM Imaging

Presentations

• SEM Essentials: Capabilities and Limitations of Scanning Electron Microscopy; and SEM Setup, Parameters and Theory for Successful Operations and Measurements
  • Download .pptx Slides
• Scanning Electron Microscopy: Principles, Techniques & Applications
  • .pptx Slides | YouTube Lecture
• Gallium Focused Ion Beam Microscopy: Principles, Techniques & Applications
  • .pptx Slides | YouTube Lecture

Simulation Software

• CASINO Electron Beam Simulation Software – simulate e-beam/specimen interactions (very useful for EDS & WDS)
• The Stopping & Range of Ions in Matter (SRIM) – simulate i-beam/specimen interactions

Calibrate Measurements with NIST Standard

• The KNI has a NIST-traceable standard against which SEM measurements can be compared. See Slides 54-55 of the SEM Presentation for details. Ask staff for help finding and using the standard in the lab.

Sample Preparation

• Use the Carbon Evaporator to make non-conductive samples conductive by applying 2-10 nm of evaporated carbon.
• Use the O₂/Ar Plasma Cleaner to remove hydrocarbons from the sample surface to avoid creating dark contamination spots on your features while imaging them.

Stubs for specimen mounting

• Stubs used for mounting specimens are considered a personal, consumable item in the KNI. There are some stubs at each Microscope which can be used by any KNI microscopy user. You can also buy your own stubs so that you can keep them clean and available to you. There are many stub geometries and configurations. If you chose to buy your own stubs, please show them to the staff microscopist prior to using them: some stubs including stubs with copper clips have large height differences and can only be used safely in specific operating conditions.

• • Buy stubs without copper clips

Guide to Choosing KNI SEMs & FIBs

• Consult this guide for help in choosing the best SEMs and FIBs for your work

Specifications

Manufacturer Specifications

• Nova 200 NanoLab Data Sheet (not all parameters apply to our instrument, see below for details specific to the KNI's Nova 200)

SEM Specifications

• Minimum Feature Size Resolved in Immersion Mode: ~5 nm
• Voltage Range: 0.2 to 30.0 kV
• Current Range: ~10 pA to 20 nA
• Apertures: 30 μm, 40 μm, 50 μm, 100 μm
• Eucentric Height: ~4.8 mm working distance (WD)
• Stage Range: ±25 mm X & Y travel, 50 mm Z travel, -12 to 58° tilt, 360° rotation
• ETD Grid Bias Range: -150 to 300 V
• TLD Bias Range: -100 to 150 V
• Ultimate Vacuum: 5e-6 mbar