Thermal stability of dysprosium scandate thin films

The thermal stability of DyScO(3) thin films in contact with SiO(2) or HfO(2) during annealing up to 1000 degrees C has been studied. It is found that DyScO(3)/SiO(2) stacks react during annealing and a phase separation into polycrystalline Sc-rich (and relatively Si-poor) DySc silicate on top of an amorphous Dy-rich DySc silicate is observed. In contrast, DyScO(3) is found to be thermodynamically stable in contact with HfO(2) and to recrystallize upon annealing. These results demonstrate that the previously reported high crystallization temperature of > 1000 degrees C for DyScO(3) is not an intrinsic material property but caused by silicate formation. (c) 2008 American Institute of Physics.