| 초록 |
The Y2O3 films were deposited by atomic layer deposition (ALD) using Y(iPrCp)2(N-iPr-amd) precursor which showed clean evaporation with no residue, and H2O reactant on Si substrate. The growth characteristic of ALD Y2O3 was investigated as the process exhibited ALD mode with good self-saturation behavior and linear growth as a function of growth cycles. By inserting ALD Y2O3 process into ALD HfO2 process, the effects of Yttrium doping into HfO2 gate dielectric have been systematically investigated. Regardless of Y/(Y+Hf) composition, all the ALD YxHf1-xO2 films exhibited constant growth rates, which is essentially indentical to ALD HfO2 growth rates. After the post-deposition annealing(PDA), it was verified that the crystallinity of all the samples were changed as varying Y/(Y+Hf) compositions. The electrical properties were evaluated by capacitance-voltage (C-V) and current-voltage (I-V) measurements. From the result of above experiments, we identified that the dielectric constant of YxHf1-xO2 film is affected by crystallinity variation which depend on the Y doping concentration. |
