Thermal conductivity of amorphous SiO2 thin film: A molecular dynamics study

Abstract

Amorphous SiO2 (a-SiO2) 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-SiO2 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-SiO2 thin films, the effect of defects induced thermal conductivity tuning was also examined. It was found that the thermal conductivity of a-SiO2 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 SiO2 (c-SiO2) 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-SiO2 with thickness beyond 4.26 nm has no significant size effect, which is consistent with the experimental results. Compared with c-SiO2 thin film, the thermal conductivity of a-SiO2 is less sensitive to defects. Particularly, the effect of spherical void defects on the thermal conductivity of a-SiO2 is followed by Coherent Potential model, which is helpful for the design of low-K material based porous a-SiO2 thin film in microelectronics.

Temperature Activates Contact Aging in Silica Nanocontacts

“…The density of the amorphous silica thus created is of 2.22 g=cm 3 , in agreement with the experimental value [71] of 2.20 g=cm 3 and previous MD simulations [40,41,57,58,63,[65][66][67]69,71]. The amorphization of the sample has been confirmed by calculating the radial distribution functions of Si─Si, Si─O, and O─O pairs whose first peaks occur, respectively, at 3.13, 1.65 and 2.67 Å, in agreement with previous MD simulations as well as with experimental results [40,41,57,58,63,[65][66][67]69,71]. The root-mean-square roughness of the surface thus obtained is of 1.56 Å, which is similar to a previously reported MD simulation whose protocol was followed here [2] and close to the experimental value [45].…”

“…This parametrization provided results in excellent agreement with experimental data [63]: namely, the structural properties and energies of the various crystalline phases as well as the amorphous phase for silica [57,63], radial distribution functions, and phonon density of states of silica glass [63]. Furthermore, it has also been experimentally validated to describe atomic rearrangements in silica glass surfaces induced using aberration-corrected transmission electron microscopy [37], transformation mechanisms [65] and thermal conductivity [65,66] in porous silica, and also the Hugoniot curves [58,67] describing the dynamic shock-induced response of silica. Additionally, a good agreement with experimental results has also been found in other mechanical properties such as the deformation behavior of amorphous silica upon indentation [40,41].…”

“…[68]. Then, in order to remove the superperiodicity of 5 nm, we improved SiO 2 amorphization by following the standard melting-quenching procedure [2, 12,13,40,41,57,58,63,[65][66][67]69]. This protocol consisted of melting SiO 2 by heating it up to 5000 K in 250 ps at zero pressure followed by a quenching to 300 K with a cooling rate of 11 K=ps.…”

Combining scanning tunneling microscope (STM) imaging and local manipulation to probe the high dose oxidation structure of the Si(111)-7×7 surface

“…Silicon dioxide is the most commonly used insulator and gate dielectric in integrated circuits and is also an important material for integration with emerging materials [1][2][3][4]. The oxidation of the silicon surface creates states which modify charge transport through the silicon, with these interface effects becoming more prominent as devices are scaled down.…”

Investigation of electrical and thermal transport property reductions in La-doped BaSnO3 films

“…2). The thermal conductivity of thin films usually increases monotonically with the thickness [44][45][46][47][48]. However, the calculated κ lat values in Fig.…”