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The crystallization behavior of Si 3 N 4 modulation layers in the multilayers and its influences on the microstructure and mechanical properties of ZrN/Si 3 N 4 multilayers were studied. ZrN/Si 3 N 4 multilayers with different Si 3 N 4 thickness were synthesized by reactive magnetic sputtering. The microstructure of the multilayers was characterized with X-ray diffraction and high-resolution transmission electron microscopy, and a nanoindentor was introduced to measure their mechanical properties. The results show that when the thickness is less than 0.9 nm, Si 3 N 4 , normally amorphous in the deposited state, could form a NaCl-type pseudocrystal structure due to the template effect of ZrN crystal layer. Crystallized Si 3 N 4 layers and ZrN template layers grow epitaxialy into columnar crystals. Correspondingly, the hardness of the films was enhanced, showing a superhardness effect. Further increasing Si 3 N 4 layer thickness, the coherent interfaces of the multilayers were damaged and Si 3 N 4 layers become amorphous, accompanied by the decline in the hardness of the films.

VN/SiO2 nanomultilayers with different individual SiO2 and VN layer thicknensses were prepared with V and SiO2 targets by reactive sputtering. The microstructure and mechanical properties of the films have been studied by X-ray diffraction, energy dispersive X-ray spectrometry, high-resolution transmission electron microscopy and nanoindentation. The results reveal that the SiO2 film synthesized by radio frequency reactive sputtering in Ar-N2 gas mixture contains no N element, normally amorphous SiO2 is forced to crystallize at very low layer thickness (2 layer gradually forms an amorphous structure and blocks the coherent growth of nanomultilayers, and the hardness of nanomultilayers gradually decreases. On the other hand, the changing of VN layer thickness has relatively small effects on the microstructure and mechanical properties of nanomultilayers.

Two series of ZrN/AlON nanomultilayers were synthesized by reactively sputtering zirconium and aluminum oxide targets in the gaseous mixture of argon and nitrogen. The thickness of ZrN layers was fixed in one of the series and the thickness of AlON layers in the other. The composition, microstructure and mechanical properties of films were characterized by X-ray energy dispersive spectroscopy, X-ray diffraction, high resolution transmission electron microscopy and nanoindentation. The investigation results indicate that during the process of Al2O3 target sputtering in the mixed atmosphere, part of oxygen atoms in Al2O3 were replaced by nitrogen atoms, leading to the formation of aluminum oxynitride, AlON. Under the influence of the “template effects” of ZrN layers, the AlON layers that used to exist as amorphous under sputtering conditions were forced to crystallize and grew epitaxially with the ZrN layers when the thickness of AlON was limited to less than 0.9 nm. Correspondingly, the hardness of multilayers was remarkably enhanced to its maximum value of 33.0GPa. A further increase in the thickness of AlON layers led to the crystalline AlON layers transforming into amorphous. The epitaxial growth of multilayers was blocked, accompanied by the decline of hardness.