Study of the depth into single crystals from which electron-channeling patterns are produced

An electron-channeling pattern is a picture of the total backscattered intensity versus the angle of incidence of an electron beam that impinges upon a single crystal in an electron microscope. This thesis deals theoretically with the depth into the crystal from which the information in the electron-channeling pattern is obtained. First, an electron-channeling pattern is calculated using the dynamical theory of electron diffraction. In order to describe the formation of the electron-channeling pattern, it is necessary to use a complex crystal potential. The information depth depends on phenomenological parameters derived from this potential. Inelastic-scattering processes are shown to control the phenomenological parameters and hence the channeling pattern and information depth. In order to draw a more explicit picture of the actual scattering that is occurring inside the crystal in the process of the formation of the electron-channeling pattern, a multiple-inelastic scattering model is constructed. In this model, the elastic scattering is described by two-beam theory in the form of two Bloch waves. It was found that two-beam Bloch waves were insufficient in capturing the full channeling behavior caused by phonon scattering although a finite information depth was calculated