Investigation of titanium nitride films deposited at room temperature by energetic cluster impact

Energetic cluster impact (ECI) deposition was applied to grow titanium nitride films on silicon (100) substrate at room temperature. Proton elastic scattering (PES), X-ray diffraction (XRD) and atomic force microscopy (AFM) were employed to characterize the composition, structure and morphology of TiNx films, respectively. The PES results reveal that the films are N-deficient and there exists a certain amount of oxygen impurity in the films. It is found from the XRD results that the structure of TiNx films is sensitive to experimental conditions such as nitrogen gas partial pressure, sputtering current and substrate bias voltage and that TiNx films are (220) preferred orientation within some range of experimental conditions. The AFM observation indicates that the films become more uniform and compact with increasing substrate bias voltage. The root mean square roughness also decreases with increasing bias voltage. Some interpretation for the above results are also given in this paper.