Transmission Electron Microscopy Study on Microstructure of Tungsten/Carbon Multilayer Films

Microstructure changes of tungsten/carbon ( W / C ) multilayer films with heat treatments were investigated by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction. When the W / C amorphous multilayer films were annealed in vacuum at 800 or 900°C, the X-ray reflectivity became 30% higher than that of as-prepared ones in association with a slight increase of the periodic spacing of the multilayers. HRTEM images of the annealed specimens revealed the existence of randomly distributed microcrystallites of W 2 C in the W layers. The increase of X-ray reflectivity was interpreted well with a simple structural model assuming the decrease of the C -atom-number density in the C layers.