LAUSR

Metrology of crystalline defects is crucial for the understanding and development of a wide range of novel materials. Hence there is a huge demand from both academia and the semiconductor industry for extended defect characterisation tools which are simultaneously rapid to use, non-destructive and capable of sampling larger areas on the nanoscale. Electron Channelling Contrast Imaging (ECCI) provides the required capability for various materials through use of scanning electron microscopes [13]. While images of extended defects, similar to those observed in plan-view transmission electron microscopy, can be obtained using ECCI (understandably with lower spatial resolution), the uptake of the technique has not been widespread. One of the major challenges limiting the use of ECCI in the wider material science community is challenges associated with characterising low atomic weight, topography-dominated and insulating samples. In the present work, we demonstrate a much wider applicability of ECCI, including for low atomic weight and insulating materials for defect metrology using gaseous secondary electron detectors (GSEDs) [4] in a field emission variable pressure scanning electron microscope. We show the advantage of performing ECCI in the gaseous environment in this case water vapour which plays a dual role in reducing the surface charges as well as acting as an amplification medium, thus providing high signal to noise micrographs. We show example from technologically important semiconductor material such as AlN, a low atomic weight and a wide-band gap material.