Atomic layer deposition of Y2O3 and yttrium-doped HfO2 using a newly synthesized Y(iPrCp)2(N-iPr-amd) precursor for a high permittivity gate dielectric
| Autor: | Clement Lansalot-Matras, Gyeongho Lee, Chang Wan Lee, Hyungjun Kim, Il Kwon Oh, Woo-Hee Kim, Min Kyu Kim, Wontae Noh, Jae Seung Lee, Jusang Park |
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| Rok vydání: | 2014 |
| Předmět: |
Permittivity
Materials science Gate dielectric Analytical chemistry General Physics and Astronomy chemistry.chemical_element Surfaces and Interfaces General Chemistry Yttrium Dielectric Condensed Matter Physics Evaporation (deposition) Surfaces Coatings and Films Atomic layer deposition chemistry Gate oxide High-κ dielectric |
| Zdroj: | Applied Surface Science. 297:16-21 |
| ISSN: | 0169-4332 |
| Popis: | We systematically investigated the effects of Y doping in HfO 2 dielectric layer, focusing on structural phase transformation and the dielectric properties of the resultant films. Y doping was carried out using atomic layer deposition (ALD) with a novel Y(iPrCp)2(N-iPr-amd) precursor, which exhibits good thermal stability without any decomposition and clean evaporation. As a result, the ALD process of the Y 2 O 3 films showed well-saturated and linear growth characteristics of ∼0.45 A/cycle without significant incubation delays and produced pure Y 2 O 3 films. Then, yttrium-doped HfO 2 films with various Y/(Y + Hf) compositions (yttrium content: 0.6– 4.8 mol%) were prepared by alternating Y 2 O 3 and HfO 2 growth cycles. Structural and electrical characterization revealed that the addition of yttrium to HfO 2 induced phase transformations from the monoclinic to the cubic or tetragonal phases, even at low post-annealing temperatures of 600 °C, and improved leakage current densities by inducing oxygen vacancy-related complex defects. A maximum relative dielectric constant of ∼33.4 was obtained for films with a yttrium content of ∼1.2 mol%. Excellent EOT scalability was observed down to ∼1 nm without dielectric constant degradation. |
| Databáze: | OpenAIRE |
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