Depth profiling of Co/Ti silicide films using total reflection X-ray fluorescence (TXRF) spectrometry combined with low energy ion beam etching (IBE) for sample preparation

Solid state phase epitaxy (SSPE) by rapid thermal processing (RTP) of Co/Ti double layers deposited on (100)-Si substrates is a common technique for the production of buried CoSi2-silicide conducting layers for microelectronics technology. The understanding of the processes during the SSPE silicide formation on the atomic scale needs the study of the elemental depth distributions with nanometer scale depth resolution of all multi-layer elemental constituents at different RTP conditions. A new experimental technique, the laterally resolved TXRF analysis line scan method across the bevelled section of the sample prepared by ex-situ ion beam sputter etching, was used to obtain the multi-element depth profiles. First results on the as evaporated Co/Ti (30 nm thick) double layer system prior to the RTP and on the final CoSi2/TixCoySiz-system (160 nm thickness) after the RTP were obtained.