|| In recent days, transparent barrier coatings on polymer substrates have been received much attention for liquid crystal displays, organic light-emitting-diode (OLED) displays, solar modules and food packing applications. It was well known that some of the organic materials and low work-function metals used in the OLED are sensitive to moisture and oxygen, which lead to the degradation of the organic based electronic devices. In order to block the device from water vapor and oxygen, an encapsulation method with a metal can or glass has been used. This kind of the conventional passivation method has weak point such as an increase in the weight and the cost. Thus, to demonstrate flexible displays having thin, flexible and lightweight properties, rather than using the conventional passivation method with metal can or glass, a thin-film passivation technique need to be developed.In the present work, Al2O3 and TiO2 thin films were deposited on poly ether sulfon (PES) and organic light emitting diode (OLED) by electron cyclotron resonance atomic layer deposition (ECR-ALD). And enhancing the WVTR (Water Vapor Transmission Rate) characteristics, e-beam irradiated onto Al2O3/TiO2 thin films. Nano-size defects were created by e-beam irradiation, the WVTR value was two orders of magnitude smaller than that of non-irradiated film. Also, bending stress induced e-beam irradiated Al2O3/TiO2 thin film maintained WVTR characteristics. Therefore, the results indicate that e-beam irradiated Al2O3/TiO2 films are highly suited for use as a passivation layer in flexible organic devices.