The Phase Change Effect of Oxygen-Incorporation in GeSbTe Films

Reflectivity changes in oxygen-incorporated Ge 2 Sb 2 Te 5 (GST) films were investigated via a laser-induced crystallization process. The crystallization process showed that the phase change speed and the laser power required for crystallization become faster and larger in GST films with a characteristic quantity of oxygen. We confirmed that a dominant grain growth mode during the laser crystallization is a major determinant for the speed of phase change in GST films with a characteristic quantity of oxygen. JMA results and changes in surface morphology indicate that the origin of the growth mode change is due to an increase in the number of initial nucleation sites produced in the oxygen-incorporated GST films. After the re-amorphization process, oxygen-incorporated GST films show more rapid and more stable phase change properties than that of GST films.