Characteristics of Defects in SiOx Thin films on Ethylene Terephthalate by High-temperature E-beam Deposition

In this paper, we investigated the characterization of silicon oxide(SiOx) thin film on Ethylene Terephthalate(PET) substrates by e-beam deposition for transparent barrier application. The temperature of chamber increases from $30^{\circ}C$ to $110^{\circ}C$, the roughness increase while the Water vapor transmission rate (WVTR) decreases. Under these conditions, the WVTR for PET can be reduced from a level of $0.57 g/m^2/day$ (bare subtrate) to $0.05 g/m^2/day$ after application of a 200-nm-thick $SiO_2$ coating at 110 C. A more efficient way to improve permeation of PET was carried out by using a double side coating of a 5-${\mu}m$-thick parylene film. It was found that the WVTR can be reduced to a level of $-0.2 g/m^2/day$. The double side parylene coating on PET could contribute to the lower stress of oxide film, which greatly improves the WVTR data. These results indicates that the $SiO_2$ /Parylene/PET barrier coatings have high potential for flexible organic light-emitting diode(OLED) applications.

고온 전자빔 증착에 의한 Ethylene Terephthalate상의 SiOx 박막의 특성 평가