Structural Change in Ag₂Te Buffer Layer During Two-Step Closed Space Sublimation of AgGaTe₂

An AgGaTe₂ layer was prepared using an Ag₂Te buffer layer. Ag₂Te layers were deposited by the radio-frequency sputtering method. We investigate the variations in the Ag₂Te buffer layer surface morphology and composition that take place during annealing. Ag₂Te films were annealed in a tube furnace. The composition and surface morphology of the Ag₂Te layer were found to vary depending on the thermal annealing temperature and duration. It was confirmed that a dewetting process in the Ag₂Te layer occurred with annealing between 200°C and 500°C, and O₂ and Mo reacted at 600°C and then became MoO₃ compounds. Mo and Te were completely desorbed from the surface at 700°C. This confirmed that the surface morphology of the Ag₂Te layer was controlled by the annealing temperature and duration.