In Figure (a), film thickness for B-C films deposited from TMB in hydrogen, is plotted as a function of the deposition time. It is seen that the deposition of boron carbon films from TMB at 700 °C can be described by a transient regime with a deposition rate of about 0.44 nm/min, and a stationary regime where the deposition rate is severely decreased to 0.02 nm/min. Figure shows that this behavior is not seen when the films are deposited in argon, where the deposition rate is about 2.8 nm/min and remains constant over time. . The blue dotted line, calculated by linear regression (R 2 = 0.991), is a guide for the eye. (c) Arrhenius plot for CVD of boron-carbon films from TMB in argon ambient (blue squares) and in hydrogen ambient (red circles). All depositions were 90 minutes. The activation energies and rate constant were EA = 202.8 kJ/mol (2.10 eV) and B = 1.96 x 10 11 nm/min/Pa n and in Ar and EA = 341.8 kJ/mol (3.54 eV) and B = 1.78 x 10 18 nm/min/Pa n in H2 where n is the order of the reaction. Such a high activation energy in H2 may be an indication of the inhibited growth rather than the actual activation energy. Around 700 °C, the deposition is limited by surface kinetics in both ambients. The lines are guides for the eye.