We had a successful and engaging symposium celebrating the launch of the NUS Invizo 6000 APT Facility — click the link HERE to find out what happened!
NUS Invizo 6000 is now open for service and collaboration!
NUS’ atom probe team has completed their advanced user training led by Rob Ulfig and the instrument is now open for collaboration and service. Reach out to xptan@nus.edu.sg for more information!
We are proud to present the latest addition to NUS's capability in nano metrology and materials characterization.
APT is the only tool that enables 3D compositional mapping at near-atomic level resolution. This is achieved by combining the principles of field evaporation and time-of-flight mass spectrometry to identify and spatially reconstruct individual atoms within a material. Typically, a focused laser pulse is used to thermally assist the field evaporation process. APT has sub-nanometer spatial resolution (~0.4nm lateral and 0.2nm depth) and chemical sensitivity of below 5 atomic parts per million (appm).
The instrument, the Invizo 6000 (only the 7th of its kind in the world) is the latest generation of APT technology developed by CAMECA (AMETEK), and is now operational at NUS.
The Invizo 6000 has several unique features when compared to the more commonly found LEAP systems, including:
- Ultra-wide field of view (250nm and above) with wider collection angle of ~120°, twice the acquisition area of LEAP systems
- Longer straight flight path (150mm) and novel double einzel lens technology for improved mass resolving power (MRP)
- Dual-beam deep UV (257.5nm wavelength) with symmetric dual illumination to ensure uniform field evaporation for higher yield and greater analysis volume of a wide range of materials (metals, semiconductors, ceramics).
- High detection efficiency with most ions leaving the specimen apex passing through the local counter electrode, ~62% ions detected and reconstructed alignment and targeting.
- Fully automated workflow of data management, specimen aligning, laser scanning, and live mass spectrum calibration and tip reconstruction.
The Invizo 6000 with its ultrawide field of view is a powerful characterization tool for advanced materials with nanoscale features of interest.
After data acquisition, visualization and analysis are performed with the software APSuite 6. This powerful software allows for many functions including drawing ROIs and isoconcentration surfaces, calculating composition profiles, as well as analyzing nanoscale clusters.
Preparation of atom probe specimens
Atom probe specimens are very fine needle-shaped tips, with apex diameter of less than 100 nm. They are commonly prepared by focused ion beam (FIB) following an established ‘recipe’ of ROI extraction and annular milling.
A more economical approach for sample preparation is electropolishing, although it is limited to metals and alloys. Using the principles of electrochemistry, we can start from a small diameter rod which is then polished in an electrochemical solution down to a very fine needle.
NUS ADAPT Invizo 6000 is now open to service and collaboration.
Email xptan@nus.edu.sg for more information.