OLED arrays made using traditional lithography equipment
In further progress to what FUJIFILM and imec had jointly developed in year 2013 where a photoresist technology was used for fabricating organic semiconductor-based devices, FUJIFILM and imec could fabricate a 40 x 40 dot colour organic LED display array with the resolution of 640ppi.
Organic LED-based displays offer higher contrast and are thinner, flexible and can refresh faster. But the display industry is facing technology challenges in fabricating reliable OLED displays using semiconductor equipment what used for traditional silicon semiconductor device manufacturing and also another challenge is fabricating higher resolution OLEDs for today's requirement such as 200 ppi in 4K television or more than 500 ppi in smart phones and wearable devices.
What the FUJIFILM and imec have done is, they have used i-line exposure system for creating sub micron patterns without damaging the less-hard organic semiconductor material. By using photolithography technique they could achieve cost competitiveness as well as higher resolution patterning on large substrates. This process could save the additional capital investment by utilising existing photolithography equipment.
By using multiple patterning process this process also allows creation of OLED array that adds a fourth color to red, green and blue, and also developing new sensors that integrate OLED with the organic photodetector.
Author: Srinivasa Reddy N