Characteristics of Al₂O₃/ZrO₂ laminated films deposited by ozone-based atomic layer deposition for organic device encapsulation

We investigated the characteristics of 100 nm-thick Al₂O₃/ZrO₂ laminated films grown by ozone (O₃)-based atomic layer deposition (ALD) at low temperature (100 °C) as thin film encapsulation (TFE). Calcium (Ca) test was performed at a relative humidity (RH) of 50% with a temperature of 50 °C to derive the water vapor transmission rates (WVTRs) of aluminum oxide (Al₂O₃)-, zirconium oxide (ZrO₂)-, and Al₂O₃/ZrO₂-laminated films. Al₂O₃/ZrO₂-laminated films exhibited better permeation barrier properties than Al₂O₃ or ZrO₂ single layer films. In Al₂O₃/ZrO₂ laminated films, permeation barrier properties improved as the number of alternating layers increased. Permeation barrier properties were closely related to the number of interfaces because of the ZrAl_xO_y phase that formed at the interface between the Al₂O₃ and ZrO₂ sublayers. The ZrAl_xO_y phase was denser than single layers of Al₂O₃ and ZrO₂ and had a homogeneous amorphous structure. The formation of a ZrAl_xO_y phase in Al₂O₃/ZrO₂ laminated film effectively improved the permeation barrier properties of the film. - Highlights: • All films were deposited by ozone-based atomic layer deposition at 100 °C. • Al₂O₃/ZrO₂-laminated films showed better barrier properties than single films. • ZrAl_xO_y phase formed at the interface between Al₂O₃ and ZrO₂ sublayers. • The number of alternating layers of Al₂O₃ and ZrO₂ affected film properties.