Localized defect states and charge trapping in atomic layer deposited-Al₂O₃ films
- In this study, the authors compared different Al₂O₃ films grown by atomic layer deposition (ALD) with the same aluminum precursor but on different substrates. The authors employed different process parameters such as thermal-ALD and plasma-enhanced-ALD using different substrate temperatures ranging from 280 °C down to room temperature. They characterized these films by resonant photoelectron spectroscopy and by electrical measurements. They established that generally the ALD-Al₂O₃ films show characteristic features of bulk Al₂O₃. For all films investigated, the authors found intrinsic defect states within the electronic band gap and identified excitonic, polaronic, and charge-transfer defect states. The authors gave an atomistic model to explain these intrinsic defects and found that their relative abundance is subject of the choice of ALD parameters and of the substrate used. They were able to relate the spectroscopic assigned in-gap defect states with the electronic charges as determined in our electrical measurements.
Author: | Karsten HenkelORCiDGND, Małgorzata KotORCiD, Dieter SchmeißerORCiD |
---|---|
DOI: | https://doi.org/10.1116/1.4971991 |
ISSN: | 0734-2101 |
ISSN: | 1520-8559 |
Title of the source (English): | Journal of Vacuum Science and Technology, A : Vacuum, Surfaces, and Films |
Document Type: | Scientific journal article peer-reviewed |
Language: | German |
Year of publication: | 2017 |
Tag: | Al₂O₃; atomic layer deposition (ALD); defect states; excitons; polarons; resonant photoelectron spectroscopy (resPES) |
Volume/Year: | 35 |
Issue number: | 1 |
First Page: | 01B125-1 |
Last Page: | 01B125-18 |
Faculty/Chair: | Fakultät 1 MINT - Mathematik, Informatik, Physik, Elektro- und Informationstechnik / FG Angewandte Physik und Halbleiterspektroskopie |