Mapping of dopants in silicon with very low energy electrons
Prof. Dr. Ludek Frank (Czech Academy of Sciences, Brno)

Abstract:
Problem of visualizing and quantitatively checking the doped areas in semiconductors will be introduced as an issue common to development and diagnostics of semiconductors structures as well as to physics of semiconductors. Discussion includes imaging by means of secondary electrons in SEM in the standard mode and in low energy mode by using the cathode lens. Optimum arrangement will be characterized and interpretation approaches reviewed. Possibility of mapping the electron states above the vacuum energy level via quasi-elastic reflection of very slow electrons will be presented with examples of non-microscopic applications of the method. Finally, results of demonstration experiments with high-resolution observation of doped structures with very low energy electrons will be presented and interpreted in terms of image contrasts of the local density of states and of the injected charge.