NOVEL PROCESSES

Universal Display and its university research partners have also developed a portfolio of processing technologies for coating of the organic thin films. Below are a few highlights:

OVPD™ Organic Vapor Phase Deposition
OVPD offers the possibility of depositing high-quality organic films with better performance and cost characteristics than conventional vacuum thermal evaporation (VTE). Developed by Universal Display and its research partner, Princeton University, OVPD works by entraining evaporated organic materials — stored in separate, thermally controlled external cells — and transporting them in an inert carrier gas (like nitrogen). Using gas flow rate, pressure and temperature, the materials can be precisely deposited through a large-area showerhead onto the cooled substrate. OVPD’s heated chamber surfaces (unlike VTE where materials collect everywhere) stay free of deposits, meaning less downtime, higher production and lower cost. It also provides sharper or graded layer interfaces, better film thickness and control/uniformity over larger areas than VTEs. Equipment based on our OVPD process technology is today sold exclusively by Aixtron AG under a license from Universal Display. Aixtron AG, headquartered in Germany, is a leading manufacturer of precision semiconductor production equipment for inorganic LEDs. Their first pre-production OVPD tool is located at Universal Display facilities in Ewing, New Jersey.

Organic Vapor Jet Printing (OVJP)
OVJP combines the high-performance of small molecule materials, that are typically deposited using VTE, with the process efficiency of a direct printing process like ink-jet printing IJP). This is achieved by flowing an organic vapor through a microscopic nozzle to form a highly collimated gas beam. As with IJP, this beam is then directed to print fine-featured organic patterns at very rapid rates. As such, OVJP offers a high-resolution printing capability with very high material utilization. It may also offer higher manufacturing cycle time and throughput than IJP because ink-jet well fabrication and a post-printing anneal step are not required. While the potential is tremendous, work remains.

Nanopatterning
Our university research team has also developed an innovative OLED patterning technique. This novel approach is based on creating a pixellation pattern after the complete OLED structure, including the cathode, has been grown. This patterning process entails a selective lift-off of the metal cathode layer. This is achieved by pressing a pre-patterned, metal-coated silicon stamp onto the unpatterned device. Under pressure, the metal coating on the stamp cold-welds to the metal cathode coating the underlying organic films. Subsequent separation of the stamp from the substrate results in removal of the cathode metal in the regions contacted by the stamp, resulting in submicron feature definition. This cold-welding followed by selective lift-off of the cathode metal has the potential to be a cost-effective, high-throughput technique for large-area OLED fabrication.