- Purswani, J.M. and Pons, A.P. and Glass, J.T. and Evans, R.D. and Cogdell, J.D., Effects of annealing on the mechanical and electrical properties of DC sputtered tantalum pentoxide (Ta2O5) thin films,
Materials Research Society Symposium Proceedings, vol. 811
pp. 63 - 68 .
(last updated on 2007/04/17)
Tantalum oxide (Ta2O5) films were deposited onto p-type silicon substrates using reactive DC magnetron sputtering, and then annealed for one hour in a dry air ambient at temperatures of 730°C, 780°C, and 830°C. Annealing was shown to reduce stress from the as-deposited sample, and resulted in a compressive stress state for samples annealed at 730°C and a tensile stress state for the other samples. Hardness values were approximately 8 GPa, with the exception of the sample annealed at 780°C that demonstrated a hardness of 13 GPa. Leakage current generally decreased with annealing, especially at the lower temperatures. Electrical breakdown was observed for as-deposited and the 830°C annealed films. Resistivities of the films ranged from 6.5 × 109 to 6.1 × 1012 Ω-cm, with the film annealed at 830°C being the most conductive. Annealing also led to an increase in dielectric constant. Dielectric constants varied from 9.3 for the as-deposited to greater than 30 for the 780°C and 830°C annealed sample. Annealing resulted in crystalline films that were close to stoichiometric.
Annealing;Magnetron sputtering;Tantalum compounds;Silicon;Leakage currents;Permittivity;Antireflection coatings;Chemical vapor deposition;Crystallization;Stoichiometry;