Cathodoluminescence as a technique for inspection, metrology, and failure analysis of microLED processing

Application Note

MicroLEDs are an important next-generation display technology offering the potential of improved performance and lower energy consumption compared to other flat-panel technologies. However, several manufacturing processing hurdles need to be addressed to scale production to mass-market volume. MicroLED displays consist of an array of directly addressable microscopic light-emitting diodes (LEDs). A current bottleneck in production is the time-consuming need to test every LED individually and replace faulty ones. Consequently, improved process development, metrology, and inspection are imperative to increase yield.

This article introduces cathodoluminescenceā€”a characterization technique based on optical spectroscopy in the electron microscope. We demonstrate how to apply this characterization technique to microLED arrays to improve device yield, reveal and characterize a range of process- and handling-induced defects, plus perform composition metrology in a fast, contactless way.