Synthesis and Mechanical Properties of TiN-AIN Thin Film Heterostructures

Abstract

AbstractTiN and AlN are promising thin film materials. There is continuing interest in their mechanical, electronic and optoelectronic properties. Our studies have shown that mechanical properties can be changed by forming thin film heterostructures of the two materials. We report on our pulsed laser deposition assisted synthesis, microstructural characterizations and mechanical properties of TiN/AlN multi-layer structures. The TiN/AlN superlattice structures are fabricated on (100) silicon substrates at different temperatures (400-800oC) and different nitrogen ambient pressures. The nano-mechanical hardness properties of the multi-layered structures were examined as a function of thickness of individual layers keeping the overall thickness of heterostructures constant. Thickness variations of the films are measured with a optical phase-shift interferometer. The mechanical properties of the TiN-AlN heterostructures have been found to be associated with interfacial interaction between layers. The interfacial interaction, in turn, depends on processing parameters the most important among which is substrate temperature.