X-ray photoelectron spectroscopy of molybdenum-containing carbon films

Abstract

Results from x-ray photoelectron spectroscopy (XPS) measurements of molybdenum-containing carbon films (Mo–C:H) deposited using an electron cyclotron resonance chemical vapor deposition (ECR-CVD) system are reported in this article. The Mo–C:H films were deposited using a technique with two Mo screen grids incorporated inside the ECR-CVD chamber. The versatility of this technique arises from the ability to control the degree of plasma ionization, sputtering rate of the metal grids, and energy of the impinging ions. Variation of the (CH4/Ar) gas flow ratio results in a change of the Mo fraction within the range of 0.32–15.11 at. %. For large amounts of Mo, the C 1s peak was split into four components with binding energies of 283.05, 284.67, 286.22, and 288.17 eV. These were identified as carbidic (metallic), polymeric, and oxidic (single- and double-bond) carbon, respectively. The presence of oxygen was detected in the films, due possibly to free-radical absorption at the film surface during deposition, or oxidation of the metallic Mo at the surface upon exposure to atmosphere. The results showed that the ECR-CVD technique is useful and effective for the deposition of Mo–C:H films with low- and high-Mo content.