| Solver: Horáček Miroslav, GA ČR GA202/03/1575, date: 01:01:2003 - 31:12:2005. The aim of this project is to use the detection of angular distribution of the signal electrons in low energy scanning electron microscope via planar image sensor for study of clean surfaces of crystalline specimens and for precise local measurment of the thickness of thin sputtered layers. To reach this aim we propose to use the arrangement with relatively high energy primary electrons whose energy is decelerated to the desired very low level only in close proximity to the specimen by the cathode lens. We propose to adapt ultra-high vacuum apparatus designed for the surface study of solids. We propose to complete this apparatus with the separator of the primary and signal electron beams of our original design plus the multichannel planar detector of signal electrons of our own design. The kernel of the detector is the thinned back-side illuminated directly electron bombarded CCD sensor with a high gain at energies of impinging electrons even below 5 keV. The detector is optimized for fast acquisition of the planar distribution of the signal electrons beam from every point of the scanning pattern and simultaneously for maximum dynamic range in the scanned image. The contrast mechanisms will be wave-optical phenomena as diffraction contrast, geometric phase contrast, quantum size contrast. The image contrast is acquired as difference between the diffraction patterns of individual points. |
