Hydrogen plasma-enhanced atomic layer deposition of hydrogenated amorphous carbon thin films

• Published in: Surface & coatings technology Vol. 344; pp. 12 - 20
• Main Authors: Choi, Taejin, Yeo, Seungmin, Song, Jeong-Gyu, Seo, Seunggi, Jang, Byeonghyeon, Kim, Soo-Hyun, Kim, Hyungjun
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-06-2018; Elsevier BV
• Subjects: Atomic layer deposition; Atomic layer epitaxy; Bromine; Carbon; Carbon tetrabromide; Contaminants; Diamonds; Fourier transforms; Hydrogen plasma; Hydrogen storage; Hydrogenated amorphous carbon; Hydroxylation; Plasma; Precursors; Raman spectroscopy; Secondary ion mass spectrometry; Substrate pretreatment; Thin films; Substrate pretreatment; Hydrogen plasma; Atomic layer deposition; Hydrogenated amorphous carbon; Carbon tetrabromide
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2018.02.082

Hydrogenated amorphous carbon (a-C:H) thin films were prepared by hydrogen plasma-enhanced atomic layer deposition (PE-ALD). The a-C:H thin films were grown at low temperatures in the range of 150–350 °C using CBr4 as the precursor and hydrogen plasma as the reactant. Raman spectroscopy, secondary ion mass spectrometry, X-ray photoelectron spectroscopy and Fourier transform infrared measurements showed that the a-C:H films consist of hydrogenated nanocrystalline sp3 diamond, disordered sp3 carbon and sp2-hybridized graphitic carbon incorporated with oxygen as a main contaminant. Moreover, the incorporation of bromine and oxygen in the a-C:H films was significantly reduced upon increasing the growth temperature from 200 to 300 °C. Surface hydroxylation and precursor exposure pretreatments were employed to saturate the adsorption of CBr4 precursors and enhance the initial nucleation of carbon during the deposition of the a-C:H thin film by the PE-ALD process. In addition, the conformal growth of a-C:H thin films on three-dimensional structures was confirmed.
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•Hydrogen plasma-enhanced atomic layer deposition of hydrogenated amorphous carbon (a-C:H) thin films was developed.•Substrate pretreatments by plasma hydroxylation and CBr4 exposure are helpful for the uniform deposition of a-C:H films.•a-C:H thin films can be deposited on three-dimensional structures in a conformal manner.