An investigation of the structural properties of hydrogenated amorphous silicon carbide (a‐Si1−xCx:H) films prepared by the plasma‐enhanced chemical vapor deposition of silane and acetylene has been undertaken using a combination of infrared (IR), Raman, and x‐ray photoelectron spectroscopy (XPS) measurements. The compositions of the silicon, carbon, and hydrogen in the films were found to be dependent on the preparation conditions. From the IR results, it is found that the Si—H bond decreases and the C—H bond increases as the film’s carbon increases. The Raman spectra showed that while the Si—Si and C—C bonds can be detected in silicon‐rich and carbon‐rich samples, respectively, the Si—C band can only be observed ina‐Si0.7C0.3:H anda‐Si0.5C0.5:H. The XPS results showed that the stoichiometry calculation from the flow rates of the reacting gases was good fora‐Si0.7C0.3:H but not fora‐Si0.3C0.7:H. Reactive ion etching of thea‐Si1−xCx:H films showed that the etch rate was dependent on the films’ carbon concentration and films prepared with acetylene as source gas were more resistive to etching compared to that prepared by butadiene. ©1995 American Institute of Physics.