Thick adherent diamond films on AlN with low thermal barrier resistance

• Published in: arXiv.org 2019-07
• Main Authors: Mandal, Soumen, Cuenca, Jerome, Massabuau, Fabien, Chao, Yuan, Bland, Henry, Pomeroy, James W, Wallis, David, Batten, Tim, Morgan, David, Oliver, Rachel, Kuball, Martin, Williams, Oliver A
• Format: Article
• Language: English
• Subjects: Aluminum nitride; Carbon; Electrons; Nitrogen; Nitrogen plasma; Photoelectrons; Pretreatment; Thermal barriers; Thermal resistance; Thick films; Transmission electron microscopy; X ray photoelectron spectroscopy; Zeta potential
• ISSN: 2331-8422

Growth of \(>\)100 \(\mu\)m thick diamond layer adherent on aluminium nitride is presented in this work. While thick films failed to adhere on untreated AlN films, hydrogen/nitrogen plasma treated AlN films retained the thick diamond layers. Clear differences in zeta potential measurement confirms the surface modification due to hydrogen/nitrogen plasma treatment. Areal Raman maps showed an increase in non-diamond carbon in the initial layers of diamond grown on pre-treated AlN. The presence of non-diamond carbon has minimal effect on the interface between diamond and AlN. The surfaces studied with x-ray photoelectron spectroscopy (XPS) revealed a clear distinction between pre-treated and untreated samples. The surface aluminium goes from nitrogen rich environment to an oxygen rich environment after pre-treatment. Cross section transmission electron microscopy shows a clean interface between diamond and AlN. Thermal barrier resistance between diamond and AlN was found to be in the range of 16 m\(^2\)K/GW which is a large improvement on the current state-of-the-art.