Silicon Oxide-Rich Diamond-Like Carbon: A Conformal, Ultrasmooth Thin Film Material with High Thermo-Oxidative Stability

摘要： Silicon oxide-containing diamond-like carbon (a-C:H:Si:O) films are a promising class of protective coatings for environmentally-demanding applications owing to their lower residual stresses and superior thermal stability and oxidation resistance relative to undoped diamond-like carbon. However, existing versions of a-C:H:Si:O deposited by traditional methods such as plasma-enhanced chemical vapor deposition (PECVD) undergo substantial degradation and oxidation at temperatures above 250 °C. This, together with the difficulty of PECVD in depositing conformal coatings on complex geometries such as high-aspect-ratio features, has limited the applicability of a-C:H:Si:O. Here, the unique capabilities of plasma immersion ion implantation and deposition (PIIID) to grow silicon oxide-rich diamond-like carbon materials that are ultrasmooth, continuous, and conformal on high-aspect-ratio topographies are explored. The high concentration of silicon and oxygen in PIIID-grown films (23 ± 5 at.% and 11 ± 4 at.%, respectively) is unrivalled for this class of materials, and drastically increases the resistance to oxidation at high temperatures, compared with PECVD-grown films. The results open the path for using a-C:H:Si:O in applications involving exposure of materials to extreme environments.