EPMA SPUTTER DEPTH PROFILING, PART-II - EXPERIMENT

Electron probe x-ray microanalysis (EPMA) has been developed into a re liable technique for surface layer analysis but, due to the relatively large depth of information, it cannot yet be applied to resolve compl ex depth distributions, i.e. layers with concentration gradients or co mplex multilayer structures. To improve the depth resolution of EPMA w e combined an ion gun with a conventional microprobe analyzer, forming the technique of EPMA sputter depth profiling (EPMA-SDP). This arrang ement allows the continuous removal of the surface and simultaneous me asurement of emitted x-ray intensities as a function of sputtered dept h. In this paper the experimental arrangement is described and first r esults are presented. The sample analysed is a Cu/NiCr/Cu/NiCr.../Si m ultilayer, a structure which could not be determined with a standard E PMA method such as beam energy variation. However with EPMA-SDP the ma ss coverage of each layer as well as its chemical composition was esta blished directly from the measured data with an accuracy of about +/-5 % relative. The theoretical background of the new technique is describ ed in part I of the paper (this volume).