Characterization of silicon nanocrystals embedded in thin oxide layers by TOF-SIMS

摘要

In this paper TOF-SIMS is used to characterize nanocrystals synthetized by ion implantation and subsequent annealing. The variation of the Si_n~- signals throughout the profile gives information about the chemical environment of the silicon atoms and allows to distinguish the silicon in the nanocrystals from the silicon in the oxide. The comparison with angle-resolved XPS measurements shows that the intensity of the Si_n~- signals depends on the oxidation state of silicon in the system. In order to evaluate nanocrystals position in the oxide layers, the problem of the depth scale calibration has been faced by comparing the results with TEM data. The values of the tunneling distance measured by TOF-SIMS and by TEM are in excellent agreement.