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Study on the OLED Thin Film Encapsulation of the Al2O3 Thin Layer Formed by Atomic Layer Deposition Method  

Kim, Ki Rak (Department of Electronics Engineering, Gachon University)
Cho, Eou Sik (Department of Electronics Engineering, Gachon University)
Kwon, Sang Jik (Department of Electronics Engineering, Gachon University)
Publication Information
Journal of the Semiconductor & Display Technology / v.21, no.1, 2022 , pp. 67-70 More about this Journal
Abstract
In order to prevent water vapor and oxygen permeation in the organic light emitting diodes (OLED), Al2O3 thin-film encapsulation (TFE) technology were investigated. Atomic layer deposition (ALD) method was used for making the Al2O3 TFE layer because it has superior barrier performance with advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the thickness of the Al2O3 layer was varied by controlling the numbers of the unit pulse cycle including Tri Methyl Aluminum(Al(CH3)3) injection, Ar purge, and H2O injection. In this case, several process parameters such as injection pulse times, Ar flow rate, precursor temperature, and substrate temperatures were fixed for analysis of the effect only on the thickness of the Al2O3 layer. As results, at least the thickness of 39 nm was required in order to obtain the minimum WVTR of 9.04 mg/m2day per one Al2O3 layer and a good transmittance of 90.94 % at 550 nm wavelength.
Keywords
Organic light emitting diodes; Thin film encapsulation; $Al_2O_3$; Atomic layer deposition; WVTR;
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