Novel mixed alkylamido-cyclopentadienyl precursors for ALD of ZrO2 thin films
| Autor: | Mikko Ritala, Maarit Kariniemi, Nicolas Blasco, Jaakko Niinistö, Christophe Lachaud, Audrey Pinchart, Markku Leskelä, Nadia Laaroussi, Kaupo Kukli, Christian Dussarrat, Ziyun Wang |
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| Rok vydání: | 2008 |
| Předmět: |
010302 applied physics
Permittivity Zirconium Analytical chemistry chemistry.chemical_element Mineralogy 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology 01 natural sciences Atomic layer deposition chemistry Impurity 0103 physical sciences Materials Chemistry Thermal stability Thin film 0210 nano-technology Tin Stoichiometry |
| Zdroj: | Journal of Materials Chemistry. 18:5243 |
| ISSN: | 1364-5501 0959-9428 |
| DOI: | 10.1039/b810922b |
| Popis: | Mixed alkylamido-cyclopentadienyl compounds of zirconium, (RCp)Zr(NMe2)3 (R = H, Me or Et) are introduced as precursors for atomic layer deposition (ALD) of high permittivity zirconium oxide thin films. Ozone was used as the oxygen source. Only slight differences were observed in the ALD growth characteristics between the three liquid precursors. The ALD-type growth mode was verified at 300 °C with a growth rate of about 0.9 A cycle−1. Good film conformality was observed, as step coverages of 80–90% were measured for films deposited onto high aspect ratio (60 : 1) trenches. As compared to the commonly used Zr(NEtMe)4 precursor, these novel precursors showed comparative volatility and growth rate but higher thermal stability, as well as lower impurity content in the deposited stoichiometric ZrO2 films. The films deposited by the (RCp)Zr(NMe2)3/O3 processes tended to crystallize in the high temperature cubic form even when the film thickness exceeded 50 nm, while the Zr(NEtMe)4/O3 process resulted in films with mixed phases. The cubic phase ensures high permittivity and thus the capacitance equivalent thickness remained extremely low, even below 0.8 nm, with low leakage current density of 10−7 A cm−2 at 1 V when a 6.4 nm ZrO2 film was deposited on TiN. |
| Databáze: | OpenAIRE |
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