Study of swift heavy-ion-induced modification in Ti/Si using x-ray standing waves.

Intermixing in a Si/Ti/Si tri-layer induced by 120 MeV Au ions has been studied. X-ray standing wave analysis combined with x-ray reflectivity has been used to get a depth profile of the Ti marker layer with an accuracy of a fraction of a nanometer. Two different thicknesses of the Ti marker layer have been used to study the possible effect of layer thickness on intermixing. In the case of a 2 nm thick Ti layer intermixing is stronger as compared to a 6 nm Ti film, which can be understood in terms of a stronger confinement of the dissipated energy in the Ti layer due to increased interface scattering of δ-electrons in the case of the 2 nm thick Ti layer. In the 6 nm thick Ti layer, intermixing is asymmetric at the two interfaces, which may be due to a possible asymmetry in the interface structure in the as-deposited film itself.