Growth and crystallization of molybdenum layers on amorphous silicon

The structure of molybdenum layers deposited by direct current magnetron sputtering onto the amorphous silicon (a-Si) layers as function of nominal layer thickness was studied by methods of transmission electron microscopy. Molybdenum layers with nominal thickness 1.5 < tMonom < 1.9 nm consist of clusters which should be considered as a transient state between strongly disordered (amorphous) state and crystal one. A transition from clusters to polycrystals takes place within the thickness range of 1.9 < tMonom < 2.5 nm. Resulting Mo crystallites have an inequiaxial form with dimensions of (3–4) × (15–30) nm2 and consist of blocks. The lateral axis of inequiaxial crystallites is parallel to 11¯0 direction. As the metal layer thickness increases Mo-crystallites take the more regular form at the expense of recrystallization.