In this contribution, we will give a comprehensive ab initio study of the elementary mechanisms which occur during the first stages of the growth. We will first characterize silicon (100) substrate the surface reactivity studying the energetic adsorption landscape on for the deposition of tungsten (W) and molybdenum (Mo), as archetype low mobility metal, and silver (Ag) and copper (Cu)) as archetype for high mobility. The most reactive surface sites will then be found will be discussed as well as the possible surface diffusion pathway, and their barrier.

We will also consider the formation of interfacial silicides layer that occurs during the early stages of metal growth under energetic conditions. For instance, we will show in the case of Mo the that the incorporation into the Si sublayer is thermodynamically favourable. The role of the concentration of the species introduced in the sub-layer on the stability of the silicide interface will be explored first. Then, the possible formation of an interfacial alloy or phase transition by diffusion of species in the bulk will also be studied.