THEORETICAL CALCULATION OF THE DEPTH RESOLUTION OF IBA METHODS

One of the most important parameters in depth profiling via ion beam analysis (IBA) is the depth resolution. Unfortunately its approximations in the literature are not general and theoretically well based. To fill this gap and help our decisions when selecting the suitable IBA method, a relatively fast and accurate algorithm was developed and implemented in a PC-code called DEPTH. The code takes into account the following effects: (1) energy and angular spread of the beam, (2) geometrical spread caused by the finite beam spot and detector solid angle, (3) straggling and multiple scattering in the sample, (4) the width of the resonance (in resonance methods), (5) absorber foil (if any) and (6) energy resolution of detection method. The energy distribution contributions coming from multiple scattering are taken into account with their statistical dependence and non-Gaussian shape. The effect of the absorber foil is approximated with its transfer function.