Electron tomographic method of nondestructive testing and reconstruction of three-dimensional structures in solid e.g. for semiconductor testing or medical applications

摘要

The method involves putting a sample of the solid in a vacuum chamber (3) and evacuating the chamber. An electron beam source (cathode 6), movable in a two-dimensional matrix, is calibrated and focused to emit into the chamber. The sample is irradiated at a matrix point with a primary electron beam (1) having energy E of at least 5 keV. The backscattered electrons are detected at the matrix point. A characteristic value and/or grayscale is defined based on the quantity of detected electrons. The values are stored and/or a grayscale image is generated. These steps are repeated for each matrix point, and the primary energy is varied to achieve a sequence of characteristic values and/or grayscale values.