P‐153L: Late‐News Poster: Vacuum Deposition of OLEDs with Feature Sizes ≤ 20um Using a Contact Shadow Mask Patterned In‐situ by Laser Ablation

Abstract

AbstractA new RGB patterning method for realizing high resolution Organic Light Emitting Device (OLED) full color displays is proposed. In this method, a plastic film is used as a shadow mask. The film is patterned by laser ablation in situ on the bottom electrode of the device, (e.g. anode), and the organic layers are then deposited on this electrode. Because the film is patterned after being put on the electrode, issues pertaining to the deformation of shadow masks and/or difficulties with aligning them precisely, are eliminated. This present study has been performed as a feasibility study for this approach. In order to assess the capability of the plastic film as a shadow mask and to test if the mounting and removal of the film on the pre‐deposited organic layer may damage to the organic layers, 20um wide OLEDs were fabricated using a pre‐patterned plastic film. Experimental results show that OLEDs can be patterned by using the plastic film mask with reasonable dimensional uniformity and without causing any significant damage to the pre‐deposited organic layer. Additionally, elemental analysis of the anode surface using Energy Dispersive X‐ray Spectroscopy (EDS) shows that anode surfaces that have been subjected to the laser ablation process are free organic contaminants or oxides, indicating that the patterning process is successful in completely removing the plastic film from the electrode surface without leaving any significant organic contaminants on the metal, and/or in causing oxidation of the metal surface in the patterned areas. These preliminary results therefore suggest that this new method is indeed promising for realizing high resolution displays, specifically 300ppi for small sized displays.