Organic electronic device

#The invention relates generally to organic electronic devices, and more particularly to device structures that improve the performance of organic electronic devices.

#For organic electronic devices, for example organic light-emitting diode displays (OLEDs), the laser ablation process has been used to remove organic materials from unwanted performance sensitive areas of the device. For illustration purposes, for one technique the first steps in the fabrication of OLED devices are the deposition and patterning of the conductive members (e.g., electrodes, such as the anodes) and conductive leads. The anode is typically indium tin oxide (ITO), and the conductive leads may include a tri-layer sandwich including an adhesion layer, a low-resistivity conducting layer, and a protective capping layer. A typical OLED conductive lead structure is Cr/Cu/Cr. After forming the anode and conductive leads, the process involves forming a cathode-separation layer followed by formation of an organic layer, such as a buffer layer (also known as a charge transport layer) (BL) and an electro-luminescent layer (EL), over the entire surface of the substrate. In the current practice in the field, the substrate then goes into the laser ablation system, where the laser beam is focused onto areas that need to be cleared of the organic layer. These include the electrode-to-conductive lead electrical contact pads, bond pads, and the frame (sometimes called the rail) around the active area upon which glue is dispensed for an encapsulating lid, which are examples of the performance sensitive areas of an OLED.

#The laser ablation process has serious drawbacks and is a weak link in the fabrication of OLED devices in large volumes. The laser ablation machine is expensive, its modules are difficult to maintain, and the machine as a whole is not easily interfaced with other process tools.

#The invention is illustrated by way of example and not limitation in the accompanying figures.

#FIG. 1 is a plan view of a portion of a substrate after forming conductive members and conductive leads to the peripheral or remote circuitry.

#FIG. 2 is a plan view of the substrate of FIG. 1 after forming cathode separation regions.

#Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.

#A process has been developed to dry etch an organic layer during the formation of an organic electronic device.

#The dry etch can be performed to expose areas of the substrate or other features, particularly those features where subsequent electrical connections or environmental seals are to be made (e.g., conductive leads, bond pads, and the rail). The advantages with using the new process in the production of organic electronic devices is that the dry etching process provides a relatively cleaner and lower cost technique to remove the organic materials, it is easy to maintain the processing equipment, it is compatible with high volume manufacturing, and (optionally) removes the need for laser ablation of conductive leads or wet etching of bond pads. Moreover, the dry etching can be controlled to avoid re-deposition of removed materials, and it provides uniform contact resistance better than encapsulation of the device and other advantages depending on the organic electronic device being constructed and application of the device. Devices manufactured using the new process have shown improvements in performance. For example, in OLED displays, lifetime improvements, device efficiency improvements, and a reduction in leakage current may be observed.