Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524
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Article

J. Korean Phy. Soc. 2009; 55(2): 590-593

Published online August 14, 2009     https://doi.org/10.3938/jkps.55.590

Copyright © The Korean Physical Society.

Characteristics of La$_2$O$_3$ Thin Films Deposited Using the ECR Atomic Layer Deposition Method

Woong-Sun Kim, Sang-Kyun Park, Dae-Yong Moon, Byoung-Woo Kang, Heon-Do Kim, Jong-Wan Park

Abstract

The characteristics of lanthanum oxide (La-oxide) films, with andwithout plasma nitridation, have been investigated. La-oxide thinfilms were grown using the electron cyclotron resonance atomic layerdeposition (ECR-ALD) technique withtris(isopropyl-cyclopentadienyl)lanthanum (La(iPrCp)$_{3})$ as thelanthanum precursor and an O$_{2}$ plasma as the reactant gas. Afterdeposition, a plasma nitridation process was performed. Plasmanitridation treatment of the La-oxide film can effectively suppressthe reaction of the La-oxide film with moisture. Therefore, thetreated films showed improved leakage current properties whenexposed to air. Self-limiting growth behavior was observed after 2-sinjections of each precursor above a deposition temperature of 300${^circ}$C. The growth rate of the La-oxide was 0.6 {AA}/cycle. Inorder to investigate the electrical properties, we usedcurrent-voltage (I-V) and capacitance-voltage (C-V) measurements.From the I-V and the C-V measurements, we found that the leakagecurrent density of the La-oxide film treated with an NH$_{3}$ plasmawas 9.80 $ imes$ 10$^{-8}$ A/cm$^{2}$ at --1 V with an equivalentoxide thickness of 2.21 nm.

Keywords: Lanthanum oxide (La$_{2}$O$_{3})$, Atomic layer deposition, High-k oxide, Rare-earth oxide, Plasma nitridation