J. Phys. IV France 11 (2001) Pr3-215-Pr3-222
Effect of the precursors on the deposition of (Ba, Sr)TIO3 filmsJ.-H. Lee1, W.-Y. Yang1, S.-W. Rhee1 and D. Kim2
1 Electrical and Computer Engineering Division, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea
2 Microelectronics Lab., Samsung Advanced Institute of Technology, San #24, Nongseo-ri, Kiheung-Eup, Yongin-City, Kyungki-Do 449-900, Korea
Ba and Sr precursors for (Ba,Sr)TiO3 films have been studied including (1) M(tmhd)2-Lewis base adduct (M = Ba or Sr, tmhd = tetramethylheptanedionate), (2) M(ketoester)2, (3) M(diester)2 and (4) M(methd)2 (methd = methoxyethoxytetramethyl-heptanedionate). In case of ketoester and diester ligands, premature dissociation of the ligand was observed while M(methd)2 shows good volatility and stability. Boiling point of Lewis base has a strong effect on the volatility of M(tmhd)2-Lewis base. Most of the Ti precursors were easily evaporated at low temperatures and thermal stability of Ti precursors could be controlled with diketone and alkoxide ligands. Ti(mpd)(tmhd)2 (mpd = methyl- pentanediol) shows higher thermal stability than Ti(i-OPr)2 (tmhd)2 or Ti(dmae)4 (dmae = dimethylaminoethoxide). To characterize the deposition behavior, (Ba,Sr)TiO3 films were deposited at the deposition temperature of 400-800°C using a direct liquid injection method. Composition uniformity and step coverage were largely affected by Ti precursors.
© EDP Sciences 2001