Pershyn Y. Interfacial interaction in multilayer nanoscale compositions based on silicon

It is shown that in multilayer nanosized compositions (MNC) Me/Si (Me: Sc, Mo, W), the interaction products are amorphous interlayers (AIs) of silicide nature with a thickness of 0.5-5.0 nm. Interlayers at different interfaces are asymmetric both in thickness and composition with a relatively high content of silicon atoms (ScSi1+x; WSi2-x; Mo5Si3) at Me-on-Si interfaces and a predominant content of metal atoms (ScSi1-x; WSi0.6±x; Mo3Si) at the Si-on-Me interfaces. It was found that the phase composition of AIs in Mo/Si MNCs significantly differs from the traditionally used MoSi2 when describing their structure. The dynamics of the transition of Mo layers from the amorphous state to the crystalline one as a function of the Mo layer thickness (tMo) was studied: the predominant part of a-Mo crystallizes with increasing tMo thickness by ~ 0.1 nm (from ~ 2.2 nm to ~ 2.3 nm); however, taking into account the appearance of the first Mo crystallites and traces of the amorphous a-Mo phase, the crystallization process is stretched by ~ 0.8 nm (from ~ 1.9 nm to ~ 2.7 nm). Such a transition may be accompanied by an increase in interface roughness. It is shown that with an increase in the thickness of crystalline molybdenum layers (tMo > 3 nm), the top AIs (Si-on-Mo interfaces) become thinner and can disappear.