Revealing the corrosion resistance of amorphous carbon films under heat shock via annealing.

Amorphous carbon films with perfect corrosion resistance have attracted scientific interest for years, but the corrosion behaviors of these films under heat shock conditions have rarely been reported. To reveal these behaviors, the corrosion properties of hydrogenated amorphous carbon (a-C:H) films at temperature of 200–400 °C are evaluated by Electrochemical tests and the variation of its structure detected via Raman spectroscopy, X-ray photoelectron spectroscopy, high resolution transmission electron microscopy and scanning electron microscopy. Under all inspected temperatures, the corrosion properties of the films are better than those of bare silicon due to the chemical inertness of the a-C:H films. In detailed, the corrosion properties improve with increasing temperature up to 250 °C, because of the densification and crystallization of the a-C:H films. Above 250 °C, the corrosion properties weakened a litter as the temperature increased, which can be attributed graphitization induced porosity and promoted the number of ion channels. In a word, the films that annealed at a temperature of 250 °C have optimal corrosion resistance. Interestingly, the surface energy of a-C:H films has little effect on corrosion behaviors. Our result shows that the a-C:H films have superior corrosion resistance even under heat shock conditions. Unlabelled Image • The I D /I G ratios of a-C:H films increase with the increase of annealing temperature. • Anticorrosion properties of a-C:H films were investigated in the annealing temperature range of 25–400 °C. • The a-C:H films with optimal corrosion resistance could be obtained by annealing at 250 °C. • The a-C:H films annealed at 250 °C own the highest contact angle and roughness. [ABSTRACT FROM AUTHOR]