Atmospheric pressure PECVD of SiO2 thin film at a low temperature using HMDS/O2/He/Ar

SiO2-like thin films were deposited at a low temperature (<50 °C) by a remote-type, atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) using a pin-to-plate-type, dielectric barrier discharge with gas mixtures containing hexamethyldisilazane (HMDS)/O2/He/Ar. The film characteristics were investigated according to the HMDS and O2 flow rates. To obtain a more SiO2-like thin film, an adequate combination of HMDS and oxygen flow rates was required to remove the –(CH3)x bonding in the HMDS and to oxidize the Si in HMDS effectively. At the optimized flow rates, the surface roughness of the SiO2-like thin film was also the lowest. By using HMDS (50 sccm) and O2 (500 sccm) flow rates in the gas mixture of HMDS/O2/He (2 slm)/Ar (600 sccm), SiO2-like thin films with a low impurity (<6.35% C) were obtained at a deposition rate of approximately 10.7 nm/min.