Growth and thermal behavior of sputtered Mo/Al2O3 multilayers

Abstract

We have examined the structure and thermal stability of Mo/Al2O3 multilayers grown on sapphire (112̄0) substrates by rf and rf-magnetron sputtering techniques. The properties of the multilayer stack have been analyzed by x-ray diffraction. A fit to the data points based on the dynamical scattering theory shows an internal oxidation of molybdenum after annealing. The multilayer system is stable up to 900 °C for 3 h. At 1000 °C, Bragg measurements show the formation of large Mo (110) crystallites, whose size exceeds one single Mo layer. Furthermore, we have performed in situ resistance measurements during the deposition of the film indicating the percolation threshold of molybdenum to be about 2.5 nm.