High-Resolution Transmission Electron Microscope Analysis of Tungsten Carbide Thin Films

Abstract

ABSTRACTElectron diffraction patterns and high-resolution transmission electron microscope (HREM) images show that the dominant phase in tungsten carbide thin films grown by plasma enhanced chemical vapor deposition is WC(1−x). The f.c.c crystal structure and the unit cell size of WC(1−x) have been determined via electron powder diffraction. The two largest and most dominant spacings in HREM images are the {111} and {002} spacings of WC(1−x). Cross lattice fringes along the two most densely populated zones of WC(1−x) are seen. The sizes and aspect ratios of nano-crystals have been measured from HREM images. Stereo analysis of individual nano-crystals has been done. Confirmation of the 3-D structure of WC(1−x) via spacings larger than 0.15 nm will require a tilt larger than 35° between images.