Infrared study on room-temperature atomic layer deposition of HfO2 using tetrakis(ethylmethylamino)hafnium and remote plasma-excited oxidizing agents

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vacuum, surfaces, and films, 2015-01, Vol.33 (1)
• Main Authors: Kanomata, Kensaku, Ohba, Hisashi, Pungboon Pansila, P., Ahmmad, Bashir, Kubota, Shigeru, Hirahara, Kazuhiro, Hirose, Fumihiko
• Format: Article
• Language: English
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.4899181

Room-temperature atomic layer deposition (ALD) of HfO2 was examined using tetrakis (ethylmethylamino)hafnium (TEMAH) and remote plasma-excited water and oxygen. A growth rate of 0.26 nm/cycle at room temperature was achieved, and the TEMAH adsorption and its oxidization on HfO2 were investigated by multiple internal reflection infrared absorption spectroscopy. It was observed that saturated adsorption of TEMAH occurs at exposures of ∼1 × 105 L (1 L = 1 × 10−6 Torr s) at room temperature, and the use of remote plasma-excited water and oxygen vapor is effective in oxidizing the TEMAH molecules on the HfO2 surface, to produce OH sites. The infrared study suggested that Hf–OH plays a role as an adsorption site for TEMAH. The reaction mechanism of room temperature HfO2 ALD is discussed in this paper.