+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
 
News Article

Fox Group uses HVPE for GaN LED production

The Fox Group has commenced production of mid-brightness GaN-based blue LEDs that have remarkable color consistency and are extremely low cost, thanks to the use of the HVPE growth technique.
The Fox Group, a start-up LED manufacturer headquartered in Ripon, California, has developed a production method for manufacturing blue GaN-based LEDs by hydride vapor-phase epitaxy (HVPE), a feat once considered impossible.

The company has established a manufacturing facility in Montreal, Canada and in mid-May shipped its first order of 460 nm FoxBlue(tm) LEDs.

The devices are AlGaN/GaN structures that do not contain either indium or quantum wells. As such, they are not high-brightness devices; typical intensities are around 1000 mcd for narrow-beam-angle LEDs or up to 3 mW for dies. “We are not competing with the big players such as Nichia, Toyoda Gosei, Cree, Osram or Lumileds, or anyone else making high-brightness InGaN LEDs,” said Barney O’Meara, the company’s vice president.

Even so, the Fox Group has three very strong advantages; the HVPE process is intrinsically low cost, it is protected by a strong patent portfolio and the LEDs have extremely good color consistency.

“The dominant wavelength is typically 460 +/- 1 nm across each wafer, from wafer to wafer, and from week to week,” said O’Meara, who attributes the incorporation of indium into InGaN/AlGaInN structures as being responsible for the much larger variations in brightness and wavelength in these devices. “Even for such applications as Christmas tree or holiday lights, color consistency is a significant issue; for sign and message board manufacturers the problem is much worse.”

Compared with MOCVD, which is used by all other manufacturers of blue GaN-based LEDs, HVPE is estimated to reduce the use of ammonia by at least an order of magnitude. Also, HVPE uses pure metals as starting materials rather than metalorganic precursors, which are around a factor of 10 more expensive per gram of metal. The fast growth rate of HVPE and the more simple device structure also help to further reduce the overall cost of the process.

The HVPE technology used to grow LEDs was developed by Technologies and Devices International (TDI), a wide-bandgap materials specialist company based in Silver Springs, Maryland. The Fox Group has an exclusive license for certain TDI patents for the field of light-emitting devices, and has moved the technology from an R&D stage to a fully-automated, reproducible manufacturing process.

The company is confident of its intellectual property position. “Besides an entirely different crystal growth process, Fox Group s LED structure is different and, we believe, non-infringing,” said O’Meara. “We have one or more patents pending in this regards, and we do not use a buffer layer.”

So what has prevented other companies from growing GaN LEDs by HVPE? Pankove and colleagues at RCA Labs more than 30 years ago grew n-type GaN by HVPE but used a metal junction for the p-side of their device. Successfully growing p-type material was one of the key factors in developing a viable growth technology, while the other was the ability to use Al in a quartz-tube reactor. The Fox Group is currently using industry-standard 2-inch sapphire wafers, although other substrates can also be used.

×
Search the news archive

To close this popup you can press escape or click the close icon.
×
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • View all news 22645 more articles
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: