The crystallization temperature of GeSbTe thin films with thicknesses between 11 and 87 nm on silicon nitride was studied through resistance versus temperature measurements. The amorphous-cubic phase transition occurs at similar to 150 degrees C for all films thicknesses, whereas the cubic-hexagonal phase transition temperature increases with film thickness, from similar to 200 degrees C for the 20 nm film to similar to 250 degrees C for the 87 nm film. The cubic-hexagonal transition occurs gradually for the 11 nm film. Implications for phase-change memory devices are discussed. (C) 2011 Elsevier B.V. All rights reserved.