Influence of Oxidant Gas of Atomic Layer Deposition on Electrical Characteristics of Al2O3 films
Year: 2018
Type: article
Abstract: We have investigated characteristics of Al2O3 thin films, which are deposited by plasma-enhanced atomic layer deposition (PE-ALD) and thermal ALD (TH-ALD) with oxygen plasma and H2O as oxidant gas, respectively, and Al(CH3)3 precursor. The Al2O3 film, which was deposited at 50℃, exhibited a large leakage current property. The positive (~1018 cm－3) and negative fixed charges (~1012 cm－2) occurred in Al2O3 film and at SiO2/Al2O3 interface by PE-ALD process at below 150℃, respectively. On the other hand, the opposite fixed charges were observed by TH-ALD process. This is due to the different reactive intermediates of Al-C-O and Al-O-Al-CH groups in Al2O3 film by PE-ALD and TH-ALD processes, respectively. The fixed charge in Al2O3 film disappeared over 200℃. The dipole (~1013 cm－2) also occurs at SiO2/Al2O3 interface and leads to positive flatband shift of 0.6 V. Therefore, we should pay careful attention to ALD condition such as oxidant gas and growth temperature considering to applications.
Source: Vacuum and Surface Science
DOI: 10.1380/vss.61.280
Authors: Toshihide NABATAME, Masayuki KIMURA, Kazuya YUGE, Mari INOUE, Naoki IKEDA, Tomoji OHISHI, Akihiko OHI
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2802081935