| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1602850 | International Journal of Refractory Metals and Hard Materials | 2016 | 5 Pages |
•Phase transformation in vacuum annealed tantalum films was studied.•The as-deposited 500 ± 2 nm thick tantalum film exhibited mixed (α and β) phases.•Vacuum annealing (at 750 °C for 1 h) resulted in the transformation of β to α-phase.•Electrical and mechanical properties were affected in vacuum annealed Ta films.
The microstructure, mechanical and electrical properties of vacuum annealed tantalum films were studied. X-ray diffraction spectra confirmed the presence of mixed (α and β) phases in the as-deposited Ta films. After vacuum annealing (at 750 °C for 1 h), the metastable β-phase was completely transformed to stable α-phase. The grain size increased (from 35 ± 3 nm to 92 ± 3 nm) with the increase in annealing temperature. The mixed (α and β) phases resulted in higher hardness and higher Young's modulus. The film annealed at 750 °C for 1 h exhibited lower resistivity (52 ± 4 μΩ-cm), lower hardness (H = 10.4 ± 1.3 GPa) and lower Young's modulus (Y = 185 ± 5 GPa) as compared to the as-deposited and annealed (at temperature < 750 °C) films. This is attributed to the phase transformation from β to α at an annealing temperature of 750 °C.
