A method has been developed for the removal from CCD images of point blemishes (PBs) ubiquitous in the acquisition of energy-filtered transmission electron microscopy (EFTEM) images. PBs arise from spurious radiation, such as X rays, impinging on the CCD detector during imaging acquisition, and form a major source of systematic error in the multivariate statistical analysis of EFTEM spectral images (SI). The method involves median filtering among images acquired sequentially, and concomitant oversampling in the energy coordinate, to remove these point blemishes without removing real spectroscopic image contrast. The method removes a major obstacle to automated nanometer-resolution chemical imaging of individual nanostructures for the purposes of statistical sampling or tomography.
Intended impact: Automated nm-resolution chemical imaging of individual nanostructures for statistical sampling or tomography
Objectives: Mitigation of significant source of systematic error in the acquisition and analysis of EFTEM spectral images
(1) TEM bright field and EFTEM phase maps of C60-implanted silicon wafer; (2) plot of eigenvalues from EFTEM SI; (3) comparison of spectral components with conventional and median-filtered PB removal .
Start Date:April 1, 2008
Lead Organizational Unit:mml
CM300FEG and Titan 80-300 analytical electron microscopes
Related Programs and Projects:
3D Chemical Imaging
Office of Microelectronic Programs