Mechanical and environmental properties of Gel1-xCx thin film

Ge1-xCx thin film was prepared by plasma-enhanced chemical vapor deposition (PECVD) using GeH4 and CH4 as precursors and its mechanical and environmental properties were investigated. The samples were measured by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectrum, FT-IR spectrometer, WS-92 testing apparatus of adhesion and FY-03E testing apparatus of salt and fog. The results show that the infrared refractive index of Ge1-xCx thin film varies from 2 to 4 with different x values. The adhesion increases with increasing gas flow ratio of GeH4/CH4 and decreases with increasing film thickness. The nanoindentation hardness number decreases with increasing germanium content. Three series films exhibit the best anti-corrosion property when the RF power is about 80W, or substrate temperature is about 150 degrees C, or DC bias is about -100V. Furthermore, increasing the gas flow ratio of GeH4/CH4 improves the anti-corrosion property of these films. (c) 2007 Elsevier Ltd. All rights reserved.