Plessey buys Cambridge spin-off for HB LEDs

MANHASSET, NY -- Gallium nitride on silicon substrates is gaining momentum as Plessey Semiconductors acquires CamGaN Ltd., a University of Cambridge spin-out, for its proprietary gallium nitride-on-silicon technology.

The technology is to help Plessey commercialize the processing growth technologies for producing GaN high-brightness LEDs on 6-inch silicon substrates. The acquisition positions Plessey the first commercial player to successfully manufacture HB LEDs on standard 6-inch silicon substrates, according to the company.

Whereas silicon carbide and sapphire substrates are expensive and difficult to scale up, Plessey claims its GaN-on-silicon solution offers cost reductions of the order of 80 percent compared to LEDs grown on silicon carbide or sapphire. This is due to the expected advantages of using a proven semiconductor process resulting in reduced scrap rates, minimum batch process times and well-proven automated semiconductor processing equipment.

Plessey expects to produce HB LEDs with 150 lumens per watt later this year. “The biggest technological challenge preventing the commercialization of HB LEDs grown on large-area silicon substrates has been the large lattice mismatch between GaN and silicon. Plessey’s new GaN-on-silicon process has overcome this challenge,” said John Ellis, Chief Engineer at Plessey.

CamGaN is led by Colin Humphreys who is affiliated with the Cambridge Center for Gallium Nitride, which has devoted over 10 years and more than $16m in funding to basic and applied research on GaN.

Besides CamGaN, a couple of start-ups are applying GaN technologies to address other applications.

Startup EpiGaN has spun out from the Inter-university Microelectronics Center research institute and is leveraging GaN-on-Si processed on 6- and 8-inch wafers for power semiconductors.(see EE Times Confidential, "Startup EpiGaN Powers GaN on Silicon Wafers").

Transphorm has begun manufacturing on 6-inch wafers and expects to move to 8-in wafers in the next two to five years for use in power conversion applications. See EETC, "GaN Startup Raises $38M To Transform Power Conversion").