Thermal conductivity of amorphous SiO(2) thin film: A molecular dynamics study

Amorphous SiO(2) (a-SiO(2)) thin films are widely used in integrated circuits (ICs) due to their excellent thermal stability and insulation properties. In this paper, the thermal conductivity of a-SiO(2) thin film was systematically investigated using non-equilibrium molecular dynamics (NEMD) simulations. In addition to the size effect and the temperature effect for thermal conductivity of a-SiO(2) thin films, the effect of defects induced thermal conductivity tuning was also examined. It was found that the thermal conductivity of a-SiO(2) thin films is insensitive to the temperature from −55 °C to 150 °C. Nevertheless, in the range of the thickness in this work, the thermal conductivity of the crystalline SiO(2) (c-SiO(2)) thin films conforms to the T(−α) with the exponent range from −0.12 to −0.37, and the thinner films are less sensitive to temperature. Meanwhile, the thermal conductivity of a-SiO(2) with thickness beyond 4.26 nm has no significant size effect, which is consistent with the experimental results. Compared with c-SiO(2) thin film, the thermal conductivity of a-SiO(2) is less sensitive to defects. Particularly, the effect of spherical void defects on the thermal conductivity of a-SiO(2) is followed by Coherent Potential model, which is helpful for the design of low-K material based porous a-SiO(2) thin film in microelectronics.