Atomic layer deposition of lanthanum oxide with heteroleptic cyclopentadienyl-amidinate lanthanum precursor - Effect of the oxygen source on the film growth and properties
| Autor: | Jaakko Niinistö, Sanni Seppälä, Jyrki Räisänen, Markku Leskelä, Kenichiro Mizohata, Mikko Ritala, Wontae Noh, Miika Mattinen |
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| Přispěvatelé: | Department of Chemistry, Department of Physics, Doctoral Programme in Materials Research and Nanosciences, Mikko Ritala / Principal Investigator, Department, Doctoral Programme in Chemistry and Molecular Sciences |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Inorganic chemistry 116 Chemical sciences chemistry.chemical_element 02 engineering and technology 01 natural sciences Oxygen 114 Physical sciences chemistry.chemical_compound Atomic layer deposition Crystallinity THIN-FILMS Lanthanum oxide DEHYDRATION 0103 physical sciences ETHANOL Materials Chemistry Lanthanum Thin film Hygroscopicity 010302 applied physics GE Metals and Alloys Hexagonal phase Surfaces and Interfaces ELECTRICAL-PROPERTIES 021001 nanoscience & nanotechnology Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry LA2O3 FILMS High-k oxides 0210 nano-technology Saturation (chemistry) |
| Popis: | La2O3 thin films were deposited by atomic layer deposition from a liquid heteroleptic La precursor, La(iPrCp)2(iPr-amd), with either water, ozone, ethanol, or both water and ozone (separated by a purge) as the oxygen source. The effect of the oxygen source on the film growth rate and properties such as crystallinity and impurities was studied. Saturation of the growth rate was achieved at 225 °C with O3 as the oxygen source. With water, very long purge times were used due to the hygroscopicity of La2O3 but saturation of the growth rate was not achieved. Interestingly, when an O3 pulse was added after the water pulse with a purge in between, the growth rate decreased and the growth saturated at 200 °C. With ethanol lanthanum hydroxide was formed instead of La2O3 at 200–275 °C whereas hexagonal La2O3 films were obtained at 300 °C but the growth was not saturative. Using the separate pulses of water and ozone in the same deposition provided the best results from the four studied deposition processes. After annealing the films deposited with the La(iPrCp)2(iPrAMD)/H2O/O3 process showed pure hexagonal phase in all the films regardless of the deposition temperature, whereas mixtures of cubic and hexagonal La2O3 were seen with the other processes. |
| Databáze: | OpenAIRE |
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