The Effect of Ti Interla Yer on the Hillock Formation of Al-0.5WT%Cu Films on the Tin/Ti/SiO2/Si Multilayer Structure

Abstract

ABSTRACTThe hillock formation of Al-0.5wt%Cu films on TiN/Ti/SiO2/Si and T1N/SiO2/Si multilayer structures was investigated by the observation of FESEM. Two types of hillocks, large and small, were observed in both multilayer structures with or without Ti after annealing at 400°C for 30 minutes. A wedge-like plateau appeared next to the large hillock in the multilayer structure without Ti interlayer. The small hillock also exhibited wedge-like morphology in the same multilayer structure. Both wedge-like plateau and small wedge-like hillocks oriented toward the same direction, which disappeared in the multilayer structure with Ti interlayer. The difference in hillock morphology on these two types of multilayer has been correlated to the difference in the extent of Al(111) texture, which was characterized by the off-axis angle and orientation factors in X-ray ψ scan analysis. The wedge-like hillocks in multilayer without Ti were aligned along the tilted direction with larger off-axis angle in ψ scan. The Al(111) texture was largely improved due to the insertion of Ti into multilayer structure.