The effect of carbon content on the phase structure of amorphous/nanocrystalline Ge1 − xCx films prepared by PECVD

In the current study, amorphous/nanocrystalline Ge1 − xCx films were prepared by plasma enhanced chemical vapor deposition (PECVD), and the effect of carbon content on their phase structure was investigated. Elemental investigation by using Rutherford backscattering spectroscopy (RBS) and structural evaluation by employing X-ray diffraction (XRD), Raman spectroscopy and high resolution transition electron microscopy (HR-TEM) were performed. The results suggested that the Ge1 − xCx films in the form of a composite structure, affected by the carbon contribution in the film, could comprise various fractions of amorphous and/or nanocrystalline germanium and amorphous carbon. With enhancing the carbon content, the crystallinity degree of the films was decreased due to increase of the volume fraction of the amorphous carbon and the intensification of the hydrocarbon radical role during the growing process.