EDAX has launched the Clarity™ EBSD analysis system—the world’s first commercially available direct detection system—that creates high fidelity EBSD patterns. This groundbreaking instrument eliminates distortions and detector noise, paving the way to unrivaled quality and sensitivity of EBSD patterns.
Existing phosphor-based EBSD systems have certain disadvantages. In particular, the thickness of a film and the grain size of a phosphorescent material can reduce the electron-to-photon conversion efficiency, and also lead to localized blooming of the signal. Consequently, the optical integration between the imaging sensor and the phosphor creates imaging artifacts in the EBSD patterns.
These slight imperfections may not be significant for Hough-based indexing, but they certainly restrict the intricate details inside an EBSD pattern for sophisticated quantitative analysis. But all these steps and associated problems from the EBSD collection chain are removed by direct detection.
EBSD orientation map collected with Clarity from an additively manufactured stainless steel sample showing deformation structure on average. Image Credit: EDAX
The Clarity EBSD Analysis System does not need a light transfer system or a phosphor screen. The technology employs a CMOS detector combined with a silicon sensor.
Within the silicon, the incident electrons create many electron-hole pairs upon impact, while a bias voltage shifts the charge toward the built-in CMOS detector, where it counts all events. This technique is so sensitive that it can identify even individual electrons.
The Clarity EBSD Analysis System, combined with zero read noise, offers unparalleled performance for collecting EBSD patterns. The system can effectively detect and examine patterns containing less than 10 electrons for each pixel.
However, even this value is somewhat ambiguous because the electron signal that falls onto the EBSD detector is uneven and just the pixels in the center of the pattern have maximum electron intensity. Closer to the edge, the pixels may only count a minimal number of electrons yet a usable EBSD pattern is still produced.
Features and Benefits
Beam Sensitive Materials Analysis
- Single-electron sensitivity is delivered with zero read noise
- Enables the analysis of materials, including perovskite solar cells that do not create usable EBSD patterns under regular beam currents
- Avoids the need for low vacuum SEM settings or conductive coatings to evaluate non-conductive materials, such as ceramics, that charge under regular beam currents
- High-quality EBSD patterns and maps can be obtained at low beam currents for studying the impacts of crystal orientation, grain size and grain boundaries
High-quality EBSD patterns collected with Clarity from (a) silicon, (b) olivine, and (c) quartz. Image Credit: EDAX
- Helps collect highly sharp EBSD patterns without using optical lenses or phosphor
- Employs high dynamic-range imaging to guarantee exceptional EBSD pattern quality
Intensity profile across (113) band from the Hikari Super and Clarity detectors showing improved contrast and sharpness with direct detection. Image Credit: EDAX