Tuesday, April 2, 2013

The Fix for OLED Yield Problems


The yield of thin film OLED devices in manufacturing is too low (LG's is estimated at less than 30%). This is the result of many factors, but one hidden cause is the failure of process control tools and the inefficiency of OLED deposition sources. Inaccuracy in film thickness sensors leads to inaccurate layer thickness. Poor source control results in organic material degradation and chemistry changes. All add up to low yield.


Better process control tools and better analysis of what is actually happening in the process chambers will vastly increase production yields. 
Most thin film OLED manufacturing lines use systems adopted from inorganic thin film deposition production. This is flawed because organic molecules do not behave in the vapor state like inorganics do**. They degrade easily. They vaporize as clusters with three dimensional characteristics. These features cause problems for thin film sensor systems, most notably density measurement and rate control due to film “packing”. Colnatec's revolutionary, patented, heated sensor technology (pdf) solves this.


  1. Evaluate of the OLED stack deposition process to determine how materials are vaporized, the type and orientation of the process control tools, and evaluate the accuracy of film thickness control
  2. Evaluate vacuum deposition conditions, including thermal condition of substrate, sensors, and sources
  3. Analyze OLED materials chemical composition, how the vaporization is controlled, and possible film breakdown; evaluate true film thickness and film growth
  4. Install and test Colnatec Tempe/Eon system based on results of analysis
  5. Analyze film growth parameter data to determine best use of materials, and control deposition process

With Colnatec's cross-platform experience and deep film growth monitoring knowledge, we can solve any deposition process control issue quickly and efficiently. sales@colnatec.com

**OLEDs are organic because they are made from carbon and hydrogen; Inorganics are non-carbon/hydrogen based compounds such as (Magnesium Fluoride or Silicon Dioxide) and metals that are typically used in the manufacture of optical and electronic components.