Physical properties of carbon films produced using a hybrid physical vapour deposition technique

Hard carbon and hydrogenated amorphous carbon films, prepared by a hybrid thermionically assisted electron beam physical vapour deposition system have been deposited at substrate temperatures between 100 and 540 °C and negative substrate bias voltages of 0-1000 V (d.c.) or 2500 V (r.f., d.c. offset). A variety of substrates have been used, including glass, tool steel (ASP23), mild steel and silicon. The nanoindentation hardness, adhesion, thermal stability, elasticity and conductivity have been correlated against deposition conditions, such as substrate bias voltage, current density, temperature, process gas, annealing temperature and hydrogen content. The stresses in the film have also been studied. Structural analysis has been undertaken using a scanning electron microscope to study the development of the film structure and the effect pf the process gas (butane or argon) and this work has confirmed the crucial importance of hydrogen in the nucleation, growth conditions and its contribution to the physical properties.