Structure and mechanical properties of a-C:H films containing nitrogen

 Nitrogen incorporated a-C:H films were deposited by r.f. plasma assisted CVD method using benzene and ammonia gas mixture as reaction gases. Composition, atomic structure and mechanical properties of the films were investigated. Nitrogen incorporation in a-C:H film reduced both the residual stress and hardness. This behavior was discussed in terms of the decrease in inter-link of sp**2 clusters by nitrogen addition. Although the residual stress could be reduced by nitrogen addition, its dependence on the negative bias voltage is identical to that of pure a-C:H films.