Ion‐beam‐induced topography and compositional changes in depth profiling

Abstract

When energetic ions penetrate and stop in solids they not only add a new atomic constituent to the matrix but they also create atomic recoils and defects. The fluxes of these entities can give rise to spatial redistribution of atomic components, which may be partly or completely balanced by reordering and relaxation processes. These latter, in turn, may be influenced by fields and gradients induced by the primary relocation processes and by the energy deposited. These will include quasi-thermal, concentration (or chemical potential) and electrostatic gradients and may act to enhance or suppress atomic redistribution. Some, or all, of these processes will operate, depending upon the system under study, when energetic ions are employed to sputter erode a substrate for depth sectioning and, quite generally, can perturb the atomic depth profile that it is intended to evaluate. Theoretical and computational approaches to modelling such processes will be outlined and experimental examples shown which illustrate specific phenomena.In particular the accumulation of implant species and defect generation or redistribution can modify, with increasing ion fluence, the local sputtering mechanism and create further problems in depth profile analysis as a changing surface topography penetrates the solid. Examples of such topographic evolution and its influence on depth protiling analysis will be given and models to explain general and specific behaviour will be outlined. The commonality of models which examine both depth-dependent composition modification and surface topography evolution will be stressed.

Estudio del crecimiento de películas delgadas de Co sobre Si(100) y SiO<SUB>2</SUB>, así como su interacción con O<SUB>2</SUB>

“…El comportamiento de la nueva superficie frente al bombardeo corresponderá a la del compuesto formado. Además al bombardear una superficie con iones energéticos no sólo se incorpora un componente más a la matriz sino que también se pueden inducir defectos y reordenamientos de los átomos existentes [48] Al realizar análisis cuantitativos, es necesario controlar los parámetros que intervienen en el proceso de decapado. Estos factores son [49]:…”