Deposition and Characterization of RP-ALD SiO(2) Thin Films with Different Oxygen Plasma Powers

In this study, silicon oxide (SiO(2)) films were deposited by remote plasma atomic layer deposition with Bis(diethylamino)silane (BDEAS) and an oxygen/argon mixture as the precursors. Oxygen plasma powers play a key role in the quality of SiO(2) films. Post-annealing was performed in the air at different temperatures for 1 h. The effects of oxygen plasma powers from 1000 W to 3000 W on the properties of the SiO(2) thin films were investigated. The experimental results demonstrated that the SiO(2) thin film growth per cycle was greatly affected by the O(2) plasma power. Atomic force microscope (AFM) and conductive AFM tests show that the surface of the SiO(2) thin films, with different O(2) plasma powers, is relatively smooth and the films all present favorable insulation properties. The water contact angle (WCA) of the SiO(2) thin film deposited at the power of 1500 W is higher than that of other WCAs of SiO(2) films deposited at other plasma powers, indicating that it is less hydrophilic. This phenomenon is more likely to be associated with a smaller bonding energy, which is consistent with the result obtained by Fourier transformation infrared spectroscopy. In addition, the influence of post-annealing temperature on the quality of the SiO(2) thin films was also investigated. As the annealing temperature increases, the SiO(2) thin film becomes denser, leading to a higher refractive index and a lower etch rate.