Depth Profiling of Ultrathin Films and Their Multilayers by DSIMS

presentation

English

Dynamic secondary ion mass spectroscopy (DSIMS) is a technique frequently used for depth profiling of elemental composition of thin films. It is generally accepted that due to atom mixing by primary ions of typical energies (100 keV), only the depth profiles of thin films thicker than 10 nm can be investigated. However, quite recently, DSIMS has been used for profiling ultrathin films of thicknesses below this value. In this applications the energy of the primary ion beam is limited to a few hundreds of eV only and thus the mixing of atoms reduced. In the contribution the ability of DSIMS to reveal depth profiles of ultrathin films (< 5 nm) and their multilayers will be demonstrated. As an example, the results on depth profiling the structures as Ni/C or Mo/Si multilayers prepared by magnetron sputtering and used for x-ray mirrors will be given. Additionally, the depth profiles of ultrathin films of Co and Al2O3 and of their magnetic multilayers will be demonstrated as well. All these films were prepared by ion beam assisted deposition (IBAD). At these measurements the depth resolution below 3 nm has been achieved and the results were checked by X-ray reflection (XRR). To obtain such a resolution, optimum measurement conditions has to be provided. In the contribution a developed imaging system helping to set these conditions (e.g reduction of the crater effect, enhancement of sensitivity) will be described.

DSIMS, multilayer, XRR, depth profiling

BÁBOR, P.; POTOČEK, M.; URBÁNEK, M.; MACH, J.; SPOUSTA, J.; DITTRICHOVÁ, L.; SOBOTA, J.; BOCHNÍČEK, Z.; ŠIKOLA, T.

27. 6. 2005

Seville