Research

The quantitative characterisation of degree of intermixing at interfaces is crucial to understand the properties of optical mirrors. A study has been done on Ru/Si interface. The experiment consisted in recording photoemission from Ru3d core levels at fixed photon energy while going through the Bragg resonance of multilayer following the evolution of component of Ru in silicide from Ru as metal itself. Results have been compared with a model calculation using the OPAL code giving the distribution of the electric field inside the sample as a function of depth and incidence angle. The evolution of Ru in silicide (red curve) and Ru (metal) (blue curve) was fitted to the experiment deriving the degree of ruthenium-silicon intermixing at the Ru-Si buried interface. It was possible to observe that the minima for ruthenium silicide and ruthenium metal were shifted. By comparing model calculations with the experiment it was possible to conclude that the intermixing profile has a σ of the order of 1nm.


 Experimental setup for buried interface analysis