Room temperature Plasma Assisted Atomic Layer Deposition Al2O3 film´s encapsulation application in Organic Light Emitting Diodes

Organic Light Emitting Diodes (OLED) are made from multilayer organic polymers and electrodes that can produce light. However, OLEDs are required to be protected from oxygen, moisture by encapsulation or seal, generally using a metal cap. The metal cap is heavier, larger and expensive. On the other hand, Plasma Assisted Atomic Layer Deposition (ALD) of Al₂O₃ film is dense, thin, and conformal [1-2]. These properties are ideal for encapsulation thin films. Room temperature (25°C) Al₂O₃ films were deposited using Cambridge Nanotech Fiji ALD system by oxygen plasma assisted atomic layer deposition with Trimethyl Aluminum (TMA) as the precursor, which had good uniformity and density across an area of 80 cm². Veeco Nanoman AFM 3D images in Fig. 1 revealed that films were smooth and uniform, as none of the films had roughness more than 1 nm at different thicknesses. Al₂O₃ films´ roughness slightly increased with increasing the film´s thickness. The Al₂O₃ film´s dielectric constant was extracted and calculated based on C-V curve, and dielectric constant 7.1 indicated a good quality of Al₂O₃ film at room temperature using plasma ALD, compared with 3 being the worst quality of Al₂O₃ film and 9 the best.