Effect of composition on surface relief morphology in TiNiCu thin films

TiNiCu films were deposited on a (100) type Si substrates by co-sputtering of TiNi and Cu targets at room temperature, and then post-annealed at 450 °C for crystallization. Significant surface relief due to martensitic transformation occurred on the film surface after cooling, and variations in surface relief morphology (the size and density of martensite crystals) have been quantified with atomic force microscopy. Energy dispersive X-ray analysis showed that the surface relief morphological difference in the TiNiCu films is due to the change in composition. It was proposed that the crystallization of the amorphous thin film during annealing behaved differently with chemical composition, which in turn induced fluctuations in phase transformation temperatures at various regions, as confirmed by differential scanning calorimeter measurements.