Growth of NbC Thin Film Using CH₄ as a Carbon Source and Reducing Agent

• Main Authors: Kwan-Woo Kim, Bum Jun Kim, Sang Hoon Lee, Tuqeer Nasir, Hyung Kyu Lim, Ik Jun Choi, Byung Joo Jeong, Jaeyeong Lee, Hak Ki Yu, Jae-Young Choi
• Format: Article
• Language: English
• Published: MDPI AG 2018-10-01
• Series: Coatings
• Subjects: transition metal carbides (TMCs); chemical vapor deposition (CVD); NbC film; reducing agent; <i>c</i>-plane sapphire; preferential orientation; domain matching epitaxy (DME)
• Online Access: https://www.mdpi.com/2079-6412/8/11/379
• ISSN: 2079-6412

Transition metal carbides (TMCs) have high melting points, hardness, and chemical stabilities in acidic media. In this work, a chemical vapor deposition method using CH₄ as a carbon source and reducing agent was employed to make an NbC film. NbCl₅ carried by Ar gas was used as an Nb precursor. An NbC thin film, deposited on a <i>c</i>-plane sapphire, exhibited a preferential orientation of the (111) plane, which can be explained by domain-matching epitaxy. A nanoindentation test showed that the NbC film with the preferential orientation of the (111) plane was stronger than that with a random orientation. Moreover, the results showed that H₂, which is conventionally used as a reducing agent in NbC synthesis, degraded the crystallinity and hardness of the fabricated NbC.