Growth and Surface Morphology of Thin Silicon Films Using an atomic Force Microscope

Abstract

AbstractThe growth and surface morphology of thin LPCVD silicon films were investigated with an atomic force microscope (AFM). Silicon films of 30 nm thicknesses were deposited on SiO2 using SiH4 at four different temperatures between 550 °C and 625 °C. These AFM results permitted visualization of silicon surface granularity, roughness, and the transition with temperature from amorphous to crystalline structure between 550 °C and 580 °C. The surface of the amorphous film deposited at 550 °C is very smooth and the film is continuous physically, while the film formed at 580 °C appears crystalline, rough and porous. At 600 °C and 625 °C the films are fully crystalline. For these higher temperature films surface roughness and the average grain size decreased significantly compared to 580 °C film. Crystallinity and film continuity were further examined by x-ray diffraction (XRD) and cross-sectional TEM measurements.