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

• All films were deposited by ozone-based atomic layer deposition at 100 °C.
• Al2O3/ZrO2-laminated films showed better barrier properties than single films.
• ZrAlxOy phase formed at the interface between Al2O3 and ZrO2 sublayers.
• The number of alternating layers of Al2O3 and ZrO2 affected film properties.

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 ZrAlxOy phase that formed at the interface between the Al2O3 and ZrO2 sublayers. The ZrAlxOy phase was denser than single layers of Al2O3 and ZrO2 and had a homogeneous amorphous structure. The formation of a ZrAlxOy phase in Al2O3/ZrO2 laminated film effectively improved the permeation barrier properties of the film.