AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP9
Irradiation Effect of Nitrogen Ion Beam on Hydrogenated Amorphous Carbon Films

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Aspects of Thin Films Poster Session
Presenter: Y. Watanabe, National Defense Academy, Japan
Authors: Y. Watanabe, National Defense Academy, Japan
S. Katoh, National Defense Academy, Japan
N. Kitazawa, National Defense Academy, Japan
Correspondent: Click to Email
Hydrogenated amorphous carbon (a-C:H) thin films were deposited on silicon single crystal substrates from toluene vapor using rf plasma at room temperature. After deposition, the a-C:H films were irradiated with a nitrogen ion beam and effects of nitrogen ion beam irradiation on surface morphology and composition were studied. Nitrogen ion irradiation was performed using a nitrogen ion beam of 0.2 to 1.5 keV for 10 min under the constant ion current density at room temperature. Surface morphology was observed by atomic force microscopy (AFM). Changes in composition and carbon-nitrogen bonding states were analyzed by X-ray photoelectron spectroscopy (XPS). Carbon structures were examined by Raman spectroscopy. AFM observations revealed that the film surface became smooth after nitrogen ion beam irradiation and notable difference in surface smoothing is hardly observed between 0.2 and 1.5 keV ion irradiation. XPS studies showed that nitrogen was absorbed near the surface of the a-C:H films after nitrogen ion irradiation and combined with carbon, resulting in carbon nitride formation. Depth profiles obtained by XPS showed that 1.5 keV nitrogen ion irradiation is more effective for carbon nitride formation than 0.2 keV ion irradiation. Carbon structures did not change remarkably after nitrogen ion irradiation. These results show that irradiated nitrogen ions are absorbed into the a-C:H films to form carbon nitride layers near the surface. The effect of the nitrogen ion energy on surface morphology and nitrogen implantation will be discussed.