The company’s p-LLO process used an excimer laser to illuminate sparsely separated die sized regions of gallium nitride at the growth interface to a sapphire wafer. The UV exposure creates gallium metal and nitrogen gas which can controllably ablate the micro-LEDs onto a receiver tool or substrate.
According to Optovate this selective array transfer process allows micro-LED manufacturers to deal with variability across GaN wafers including growth defects, colour and forward voltage. What's more, the selective optical addressing capability of p-LLO enables pre-transfer characterisation data on wafers to be coded into the micro-LED extraction patterns and used for seeding and back filling micro-LED backplanes, optimizing overall yield.
For micro-LED growth substrates such as silicon that aren’t transparent in the ultraviolet, Optovate also anticipates p-LLO process modifications in its IP, with the same performance enhancements.
“When we started work on what have now come to be known as micro-LEDs we were counter trend – everyone wanted bigger LEDs for lighting while we were predicting the future was sub 100 micrometre sized devices. That meant we had to develop our own manufacturing strategies for both micro-LEDs and micro-optics. The industry has now understood this and we are pleased to present results from those early IP insights”, said Jonathan Harrold, co-founder of Optovate in a statement.
Optovate – www.optovate.com