Correlation between interfacial electronic structure and mechanical properties of ZrN/SiNx films

The ZrN/SiNx double-layers with different density of SiNx layers, which was controlled by applying different substrate bias for depositing SiNx layers, were synthesized for investigating the interfacial electronic structure. Results indicated that the interfacial electrostatic polarization existed as the ZrN and SiNx bond with each other to form a heterojunction, since the electrons donated from ZrN layer to SiNx layer. Moreover, the degree of polarization was affected by the density of SiNx layer. The corresponding ZrN/SiNx multi-layers were deposited for studying the correlation between interfacial electronic structure and mechanical properties. The results of hardness test implied that the interfacial electrostatic polarization would enhance the hardness to a certain extent.

► Electrostatic polarization existed in the ZrN/SiNx interface.
► Interfacial electronic polarization increases with increasing Vb for SiNx layers.
► Hardness values for ZrN/SiNx   multi layers increase with increasing VbSiNx.
► Interfacial electrostatic polarization enhances the hardness to a certain extent.