Enhancing the thermal conductivity of polymer-assisted deposited Al₂O₃ film by nitrogen doping

Polymer-assisted deposition technique has been used to deposit Al₂O₃ and N-doped Al₂O₃ (AlON) thin films on Si(100) substrates. The chemical compositions, crystallinity, and thermal conductivity of the as-grown films have been characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and 3-omega method, respectively. Amorphous and polycrystalline Al₂O₃ and AlON thin films have been formed at 700 ℃ and 1000 ℃. The thermal conductivity results indicated that the effect of nitrogen doping on the thermal conductivity is determined by the competition of the increase of Al–N bonding and the suppression of crystallinity. A 67% enhancement in thermal conductivity has been achieved for the samples grown at 700 ℃, demonstrating that the nitrogen doping is an effective way to improve the thermal performance of polymer-assisted-deposited Al₂O₃ thin films at a relatively low growth temperature.