Low voltage imaging and X-ray microanalysis in the SEM: challenges and opportunities

Low voltage imaging, X-ray microanalysis and X-ray mapping has become very important for the investigation of nanomaterials and their surfaces. This is especially true for low voltage imaging of non-conductive samples and beam sensitive samples. Operating the SEM at lower accelerating voltage allows for greater surface sensitivity, the ability to minimize charging effects, nanometre scale lateral X-ray spatial resolution and nanoscale X-ray depth sensitivity. Determining the correct accelerating voltage for imaging in a SEM is dependent on the instrument's operating performance at low voltage, the material being viewed, and other factors that limit effectiveness of low voltage microanalysis, which will be discussed in this paper.