| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | G. 나노/박막 재료 분과 |
| 제목 | Al2O3 Thin Film Encapsulation by Ozone-based Atomic Layer Deposition |
| 초록 | Organic light-emitting diodes (OLEDs) have advantageous features, such as their high efficiency, fast response time, flexibility and transparency, etc. However, the permeation of water vapor and oxygen into active layers will cause damage or malfunction. For a stable device operation, a water vapor transmission rate (WVTR) on the order of 10−6 g/m2/day is mandatory. In order to realize long lifetime OLEDs, various encapsulation technologies have been researched extensively. Among them, thin film encapsulation (TFE) is considered to be requisite for future flexible electronic devices. Comparing different TFE techniques, thin films deposited by atomic layer deposition (ALD) have been shown to provide superior protection for organic devices. Up to now, most reported Al2O3 ALD barrier films have been obtained using H2O and O2 plasma as a reactant. Generally, H2O is a relatively weaker oxidizing reactant, and thus H2O-based Al2O3 requires long process time. On the other hand, Al2O3 by plasma enhanced atomic layer deposition (PEALD) exhibits poor WVTR and insufficient OLED lifetime. An alternative to supplement these limiting factors is to use an ozone as the oxidant reactant. This study describes the moisture permeation barrier properties of Al2O3 thin films deposited by ozone-based ALD at 100 °C. Trimethylaluminum (TMA) and O3 were used as precursors of Al and O, respectively. The ozone concentration was varied from 100 to 400 g/m3 with an increment of 100 g/m3. Compared to other oxidants, an ozone is a strong oxidizing agent and highly volatile. Thus an ozone reactant is a promising alternative oxygen source to improve the barrier properties and speed up the film fabrication. The thickness and density of the deposited Al2O3 were determined by a X-ray reflectivity (XRR), and the refractive index measurement was analyzed using a spectroscopic ellipsometer (SE). The chemical structure and film composition of the films were evaluated by X-ray photoelectron spectroscopy (XPS). The surface morphology was observed by using an atomic force microscope (AFM). The moisture barrier performance of thin films is analyzed by WVTRs, and a Ca test was performed to calculate WVTRs by using the oxidization properties of calcium layer. |
| 저자 | Seokyoon Shin, Giyul Ham, Joohyun Park, Juhyun Lee, Hyeongsu Choi, Seungjin Lee, Sejin Kwon, Hyeongtag Jeon |
| 소속 | Hanyang Univ. |
| 키워드 | <P>Al<SUB>2</SUB>O<SUB>3</SUB>; Thin Film Encapsulation; Ozone; Atomic Layer Deposition; Water Vapor Transmission Rate</P> |
