Precise, scalable shadow mask patterning of vacuum-deposited organic light emitting devices

We demonstrate a scheme to pattern vacuum-deposited, small molecular weight organic light emitting diodes (OLEDs). Both the organic thin films and the metallic electrodes are patterned by shifting the position of a single shadow mask which accompanies the substrate throughout the deposition process. A full color, stacked OLED (SOLED) has been fabricated using this technique. The substrate movement relative to the mask was manually controlled to a root; mean square accuracy of +/-8 mu m using a mask translating fixture. The performance of the patterned SOLED is comparable with that of devices fabricated by conventional, low tolerance methods. The limits to the display fill factor and resolution using this technique are discussed. The technique is generally applicable to all structures requiring precise patterning of vacuum-deposited thin films. (C) 1999 American Vacuum Society. [S0734-2101(99)05505-0].