Structural and Nanomechanical Properties of Cu (InxGa1–x)Se2 Thin Films Fabricated by One-Step Sputtering

The structural and nanomechanical properties of Cu(InxGa1–x)Se2 films deposited on Si(100) substrate at different temperatures (25°C to 500°C) by one-step radiofrequency magnetron sputtering are discussed. X-ray diffraction analysis revealed a dominant (112) diffraction peak. The surface morphology was examined by field-emission scanning electron microscopy and atomic force microscopy. The film composition was examined by electron probe microanalysis. The Cu/(In + Ga) and Ga/(In + Ga) ratios were 0.9 and 0.3, respectively. Nanoindentation conducted in conjunction with scanning electron microscopy revealed that the films suffered severe delamination-type fracture due to poor adhesion to the Si substrate. The hardness of the films was not influenced by the substrate temperature except for the film grown at 500°C. The hardness was greatly affected at depths greater than the thickness of the film due to its poor adhesion. At deep indents, the hardness results agreed closely with that of the Si substrate.