Deep UV: The Road To Mass Production
SETi's recent Nitek acquisition looks set to deliver cheaper UV LEDs, faster than ever before. Compound Semiconductor reports.
Nitek acquisition brings in new markets for UV LED developer, SETi.
Late last year, UV LED maker, Sensor Electronic Technology (SETi), bought the commercial operations of competing LED manufacturer, Nitek, a move that propels the company towards cheaper, mass production.
As was stated at the time: 'the transaction combines two complementary companies to become the largest UV-focused LED developer and manufacturer in the world with the lowest cost of ownership'.
Renowned for manufacturing deep UV LEDs for spectroscopy as well as aerospace and defence markets, SETi has also been focusing on applications for more consumer-oriented sectors including disinfection and healthcare.
And with Korea-based UV and blue LED maker, Seoul Viosys, and affiliates, taking a major stake in the company earlier this year, the company is primed for the necessary manufacturing expansion that these markets will demand.
"We have in-house capacity at our chip fab and packaging facility in South Carolina and can produce significant volumes of product through this facility - around several million units a year," highlights director of marketing and sales, Tim Bettles.
"And now Seoul Viosys can utilize our epi-wafers and manufacture extremely high volumes through its chip fabrication and packaging facilities as well," he adds
.High power, small footprint: UV LEDs are being developed for water sterilisation, medical analytical instrumentation and more.
So what exactly does Nitek bring to SETi right now? The University of South Carolina spin-off launched in 2007 to commercialise III-nitride technologies, and supplies both near-UV and deep-UV LEDs.
However, crucially for SETi, Nitek has developed a cost-effective and high volume manufacturing process for deep-UV LEDs; not an easy task. While UV-A LEDs, emitting at 400 to 315nm, are fabricated by growing InGaN-based epilayers on sapphire substrates via the same MOCVD methods used in visible LED markets, UV-B and UV-C wavelengths use a completely different materials structure.
Manufactured by only a handful of companies, these UV-B and UV-C devices - which emit at 315 to 280nm and 280 to 210nm - are fabricated by depositing AlN layers onto either a bulk AlN crystal or a sapphire wafer.
SETi has focused on the latter, using migration enhanced MOCVD and migration enhanced lateral epitaxial overgrowth to grow its AlN-on-sapphire UV LEDs.
Bettles declines to provide detail on Nitek's manufacturing process, simply stating: "We have secured manufacturing equipment and personnel."
But as he emphasises: "Prior to acquiring Nitek, we had the largest epi-wafer capacity in the world for deep UV LEDs, but Nitek will allow us to reach even higher manufacturing volumes and reduce the cost of our epitaxy processes per chip."
"And now we're seeing design wins into consumer products, this will really help us to drive deeper into these markets," he adds.
So where next for SETi? The company launched its surface mount packaged LEDs around 18 months ago, and market adoption is gathering momentum.
It also recently signed a long-term agreement with US-based Wellness Center subsidiary, Psoria-Shield, to develop UV-B LEDs for phototherapy systems. What's more, as part of the Nitek deal, SETi has acquired the exclusive right to sell Seoul Viosys UV-A LEDs to North America.
"We'll be developing our processes to make sure we have the largest capacity and most cost-effective products on the market," says Bettles.
Importantly, and unlike longer wavelength UV-A LED markets, the SETi director doesn't expect imminent competition from Asia-based visible LED manufacturers, keen to tap into new markets.
"We all use MOCVD but the process window is very different for deep UV LEDs, which is a large barrier to entry," he says. "Low cost white LED companies in China and the rest of Asia can't move into this market so easily."
"So we now see ourselves as by far the largest company that is also a total UV LED provider and between Seoul Viosys and SETi, we really want to be the number one UV LED producer," he adds.