Amorphous thin GeSbTe phase-change films prepared by radical-assisted metal-organic chemical vapor deposition

Amorphous thin Ge2Sb2Te5 films were deposited by MOCVD (metal organic chemical vapor deposition) on three-dimensional structures. Ammonium gas, used as a reactant, reduced the deposition temperature to 150 °C, which is lower than that of metal-organic precursors. Introducing nitrogen and hydrogen radicals made by decomposition of the ammonium gas further reduced the growth temperature. The lowest growth temperature producing a realistic growth rate was 100 °C. Phase-change memory cells made of MOCVD-grown films were confirmed to have operation and reliability characteristics as good as those of conventional cells made of sputter-deposited films.