고주파 원거리 플라즈마 원자층 증착기로 증착된 Al2O3 박막의 수분 차단막 특성에 대한 연구

Abstract

Organic Light Emitting Display (OLED) has been the next generation display in the world by using its vivid color, wide angle view, and slim thickness. These features are possible because OLED use organic materials as a light sources. Because organic materials can make the light with current by itself, a lot of features are possible. These organic materials, however, need additional encapsulation process against atmosphere, because organic materials are vulnerable to H2O or O2 in the atmosphere. Organic materials are degraded by contacting H2O or O2. Therefore, encapsulation process for protecting inner organic materials is needed. This method is called as encapsulation, and glass encapsulation is the method which is now being used as OLED encapsulation. This glass method has a strong point to protect organic materials from atmospheric gases such as H2O or O2 under 10-6 level of WVTR, but this has a limit to be flexible OLED for its solidness. In order to achieve advanced flexible OLED, another encapsulation method is needed. The new method has to be possible to be applied to flexible application with the same level of WVTR value such as 10 -6. With respect to this, thin film encapsulation method with Al2O3 has emerged recently. This TFE can show both low WVTR and flexible features. Especially, Al2O3 thin film using RPALD is a representative method in the OLED flexible display by using thermal stability and crystal structure of Al2O3. And RPALD can deposit thin film, by using O2 as a reactant, with good step coverage, thickness uniformity, and defect free layer, thus Al2O3 by RPALD becomes a good item for OLED TFE. In this study, we determine the moisture permeation barrier characteristics by using three parts dealing with RPALD and Al2O3. The first part is about the moisture permeation barrier characteristics as plasma power of RPALD increasing, and the second part is about the new item of TFE using Al2O3. This new item is multi-density layer of Al2O3 which is the study of the Al2O3 layer having different density and deposition condition. Lastly, the third part is about the relationship between ion density and crystal structure. And in these papers, the analysis tools such as AES, XPS, XRD, XRR, FHM, TEM, and ERD were used for deeper analysis about moisture permeation barrier characteristics of Al2O3 thin films deposited by RPALD.