Structure of Sputtered Molybdenum Disulfide Films at Various Substrate Temperatures

Abstract

MoS2 films (300 to 400 Å) were radio-frequency sputtered on aluminum and nickel surfaces at elevated, ambient, cold water, and liquid nitrogen temperatures. Electron transmission micrographs and electron diffraction patterns were taken to determine the structural growth. These transmission micrographs revealed that sputtered MoS2 films at ambient and elevated temperatures (320 and 150 C) formed an irregular network of ridges. The electron diffraction patterns of these films showed relatively sharp diffraction rings, indicating crystallinity. At water temperatures (∼7 C), ridge formation was extensively reduced or completely eliminated. The transmission micrographs of sputtered films at liquid nitrogen temperatures revealed a continuous featureless film. The electron diffraction patterns showed broad, diffused rings indicating an amorphous film. The transmission micrographs of a post annealed (425 C) MoS2 film sputtered at liquid nitrogen temperature revealed the tendency for ridge formation. Electron diffraction patterns also showed increased sharpness of the diffraction rings.