Threshold displacement energy of amorphous SiO₂: A molecular dynamics study

Amorphous SiO₂ is a vital insulation or isolation material in modern silicon-based devices and chips, which is exposed to irradiations of energetic particles when working in space environment. In order to evaluate the radiation resistance of a-SiO₂, the threshold displacement energy (TDE) with molecular dynamic simulations is calculated. We found a linear dependence of the TDE of O atoms on the Si–O–Si bond angles, which corresponds to a reduction in the stresses exerted on the central O atom as the bond angle increases. The further exploration about the oxide manufacturing process showed that the higher annealing temperature increases the probability of Si–O–Si bond angles in the range of 135°–155°. This work will shed light on the promotion of anti-radiation ability of silicon-based devices.