Morphology and crystallization kinetics in HfO2 thin films grown by atomic layer deposition
| Autor: | B. W. Busch, Paul M. Voyles, M. Bude, Hao Gong, David A. Muller, M.-Y. Ho, S. K. Lahiri, Petri Räisänen, M. E. Loomans, Martin L. Green, W.H. Lin, Alex See, Glen D. Wilk |
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| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 93:1477-1481 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | We report the effects of annealing on the morphology and crystallization kinetics for the high-κ gate dielectric replacement candidate hafnium oxide (HfO2). HfO2 films were grown by atomic layer deposition (ALD) on thermal and chemical SiO2 underlayers. High-sensitivity x-ray diffractometry shows that the as-deposited ALD HfO2 films on thermal oxide are polycrystalline, containing both monoclinic and either tetragonal or orthorhombic phases with an average grain size of ∼8.0 nm. Transmission electron microscopy shows a columnar grain structure. The monoclinic phase predominates as the annealing temperature and time increase, with the grain size reaching ∼11.0 nm after annealing at 900 °C for 24 h. The crystallized fraction of the film has a strong dependence on annealing temperature but not annealing time, indicating thermally activated grain growth. As-deposited ALD HfO2 films on chemical oxide underlayers are amorphous, but show strong signatures of ordering at a subnanometer level in Z-contrast scannin... |
| Databáze: | OpenAIRE |
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