Controlling Thermal Diffusivity, Residual Stress and Texture in W/Cu Nano-Multilayers by Magnetron Chamber Pressure Variation

The effect of magnetron deposition pressure during manufacture of W/Cu nano-laminates on their thermal diffusivity, residual stress depth profiles and texture was analysed. A strong correlation between these properties and the Ar working pressure was confirmed experimentally via a combination of Transient Grating Spectroscopy, Focused Ion Beam ring drilling, and cross-sectional high resolution SEM and EDX characterisation. The underlying mechanisms controlling thermal diffusivity and residual stress can be related to the defect evolution during sputter deposition, which is largely controlled by the interaction of the working gas and the sputtered metal atoms.