Stress induced texture and shape memory trench in TiNiCu films

Film texture and surface morphology of a crystallized TiNiCu film (deposited at 350 °C and post annealed at 450 °C in vacuum on a four inch wafer) have been characterized. X-ray diffraction analysis showed a preferred (002) martensite orientation at room temperature and a strong (110) austenite texture at temperature above 80 °C. Surface trenches were observed on the crystallized film surface at room temperature and disappeared when the film was heated to a high temperature above 80 °C. The formation of the strong texture and shape memory trenches is attributed to a significant stress evolution during post-annealing process. The variation of the trench morphology on the surface of the TiNiCu film surface over a four inch wafer after annealing has also been studied.