Optimization of a SiO _x /SiN _x O _y C _z multilayer structure for a reliable gas diffusion barrier via low-temperature plasma-enhanced atomic layer deposition

Thin film encapsulation (TFE) using a multilayer film composed of SiO _x and SiN _x O _y C _z layers deposited by plasma-enhanced atomic layer deposition is demonstrated. To investigate the mechanism of suppressed moisture penetration for the multilayer film, chemical analyses were performed using Fourier transform infrared and Auger electron spectroscopy, and the encapsulation ability was evaluated using the water vapor transmission rate (WVTR). The encapsulation ability of the multilayer film is affected by the nitrogen content in the SiN _x O _y C _z layer and the number of interfaces in the multilayer film. Consequently, TFE using a multilayer film of 20-nm-SiN _x O _y C _z /20-nm-SiO _x /20-nm-SiN _x O _y C _z resulted in excellent encapsulation ability, with a WVTR of 7.63 × 10 ⁻⁴ g m ⁻² day ⁻¹ .