In recent years hard carbon films have attracted much attention due to their high hardness and wear resistance.¹ Deposition profile of hard carbon films in trenches is one of the concerns. We have succeeded in controlling deposition profile of Cu in trenches of 100 nm in width, and have realized sub-conformal, conformal and anisotropic deposition profiles using H-assisted plasma CVD.^2-4 Here we report these three deposition profiles of carbon films obtained using the H-assisted plasma CVD. Experiments were performed using the H-assisted plasma CVD reactor, in which a capacitively-coupled 28 MHz main discharge and an inductive-coupled 13.56 MHz discharge for an H atom source were sustained.^2-4 This reactor provided independent control of dissociation of deposition material and generation of H atoms. Toluene diluted with H₂ and Ar was supplied at flow rates of 80sccm and 10sccm, respectively. The total pressure was 13 Pa. First, we have studied dependence of deposition rates at the bottom and sidewall of trenches on discharge power of the H atom source. The deposition rates tend to decrease with increasing the power, probably because the flux of H atoms, which etch carbon films, on the surfaces increases. Next, we have studied dependence of the deposition rates on kinetic energy of ions impinging on the surfcases. The deposition rate at the bottom increases significantly with increasing the kinetic energy of ions, while that at the sidewall does not. Irradiation of high energy ions modifies carbon films into a hard structure and the etching rate of such hard carbon films is considerably reduced.^1,5 Another important parameter for deposition profile control is identified to be the substrate temperature. By tuning the H atom flux, ion energy, and substrate temperature, we have realized sub-conformal, conformal and anisotropic deposition profiles of carbon films. Film qualities such as atomic compositions, structure will be presented at the conference.

¹ J. Robertson, Materials Sci. and Engineering R, 37 129-281 (2004).

² K. Takenaka, M. Shiratani, M. Takeshita, M. Kita, K. Koga, and Y. Watanabe, Pure Appl. Chem., 77, 391 (2005).

³ K. Takenaka, M. Kita, T. Kinoshita, K. Koga, M. Shiratani, and Y. Watanabe, J. Vac. Sci. Technol., A22, 1903 (2004).

⁴ J. Umetsu, K. Koga, K. Inoue, H. Matzuzaki, K. Takenaka, M. Shiratani, Surf. Coat. Technol., 202, 5659 (2008).

⁵ A. von Keudell, W. Jacob, J. Appl. Phys. , 79 1092 (1996).