For the most part, materials of technical, industrial, or engineering importance are crystalline to some degree, and the interaction of an incident or analyzing electron beam with such materials will be influenced measurably by this crystal structure, or some other regularity in the arrangement of the constituent atoms. In the simplest approximation, people can consider diffraction from a crystal line lattice as a kinematic scattering process ideally described by wave reflection from planes as expressed in the Bragg equation. However, whereas x-ray diffraction can be described as photon reflection from a spherical nucleus, the scattering of an electron from a lattice atom must consider its potential distribution. The microprobe reflection high energy electron diffraction (RHEED) is a kind of scanning electron microscopy which uses reflection diffraction spot intensities as an image signal. Consequently, crystallographic or related structural features associated with a surface condition or specific surface treatment are elucidated by the HEED reflection mode.