Thermal stability of the phase composition and structure of hafnium diboride films

The thermal stability of the composition and crystal structure of hafnium diboride films grown by rf magnetron sputtering have been studied by X-ray diffraction and secondary ion mass spectrometry. We have assessed the effect of high-temperature annealing in air on the phase composition and structure of the hafnium diboride films. The results demonstrate that annealing produces a HfO2 oxide layer on the surface of the HfB2 film. Raising the annealing temperature from 600 to 1000°C leads to an increase in the thickness of the oxide layer from 100 to 600 nm and to the formation of a multilayer HfB2-HfO2 coating.