Hollow-cathode chemical vapor deposition of thick, low-stress diamond-like carbon films

• Published in: Thin solid films Vol. 714; no. na; p. 138394
• Main Authors: Miller, J., Ceballos, A., Bayu Aji, L.B., Moore, A., Wasz, C., Kucheyev, S.O., Elhadj, S., Falabella, S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 30.11.2020; Elsevier
• Subjects: Amorphous hydrogenated carbon; Coatings; condensed matter physics; Diamond-like carbon; MATERIALS SCIENCE; nanoscience and nanotechnology; Plasma chemical vapor deposition; plasma physics; solid state physics; Amorphous hydrogenated carbon; Diamond-like carbon; Plasma chemical vapor deposition; Coatings
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2020.138394

•Smooth, low-stress, amorphous hydrogenated carbon films via plasma chemical vapor deposition.•Higher density films grown when using Ar plasma compared to N2 or H2 plasma.•Plasma confinement via a magnetic field suggests improved gas ionization. A radio-frequency (RF), hollow-cathode plasma source with confining magnetic field is described for the chemical vapor deposition of thick ( >  10 µm), amorphous diamond-like carbon ablator films for inertial confinement fusion applications. Plasma is characterized by optical emission spectroscopy, while properties of the resultant films are measured by a combination of profilometry, Rutherford backscattering spectrometry, elastic recoil detection analysis, X-ray diffraction, Raman spectroscopy, and atomic force microscopy. The dependence of the deposition rate, film density, elemental composition, self-bias and residual stress is reported as a function of RF power. Higher density films were found when using Ar plasma, than N2 or H2 plasma. The coatings produced are x-ray amorphous, exhibit low compressive stress ( ~ 100 MPa), high density ( < 1.7 g/cm3), hydrogen content of  ~ 30 at.%, and a low average roughness of 0.75 nm. Applications of these films as tunable-density ablators for inertial confinement fusion experiments are discussed.