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News

23 August 2007

 

TDI demonstrates first HVPE-grown blue and green InGaN LEDs

Nitride material manufacturer Technologies and Devices International Inc (TDI) of Silver Spring, MD, USA says it has fabricated the first epitaxial structures for blue (450–490nm) and green (490–510nm) indium gallium nitride (InGaN)-based LEDs grown entirely by hydride vapor phase epitaxy (HVPE).

The new LEDs will be reported at the 4th China International Forum & Exhibition on Solid State Lighting, Shanghai (22-24 August) and the 1st International Conference on White LEDs and Solid State Lighting, Tokyo (26-30 November), and will be displayed at the 7th International Conference on Nitride Semiconductors, Las Vegas (16-21 September).

“HVPE is known as very cost-effective method to fabricate thick GaN and AlN layers with low defect density.  Such materials are typically used as substrates for GaN-based devices,” says president and CEO Vladimir Dmitriev.  “However, despite fast deposition rates, low defects and strong economics, HVPE has not been considered for the fabrication of device structures with nanometer-thick layers needed to make high efficiency light-emitting devices.  Another limitation has been the absence of HVPE-grown high-quality InGaN materials used as light emitting regions of LEDs and LDs (laser diodes), he adds. Now, using TDI’s HVPE process and equipment, these issues have been solved, Dmitriev claims.  Demonstrating the devices using HVPE is an important step in the development of low-cost LEDs for solid-state lighting applications, he adds.  

“Recently, TDI has completed development of novel HVPE technology to fabricate all major building blocks for light-emitting devices, including epitaxial growth of GaN and InGaN quantum wells and superlattice structures with sharp interfaces, highly efficient n-type and p-type doping for as-grown materials, and InGaN layers for the whole composition range,” adds R&D director Dr Alexander Usikov. “Now, growth rates of AlGaN, GaN, and InGaN materials by HVPE can be controlled from very low levels of about 0.5 micron per hour needed to make quantum well structures and up to hundred microns per hour to grow thick low-defect layers.  There is no other epitaxial method with such a wide range of deposition rates,” he claims. 

Usikov adds that TDI is working to increase InGaN content in the LED structures toward the fabrication of yellow and potentially red light-emitting devices.

See related items:

TDI introduces InGaN substrates

TDI to sample InGaN epi in early 2007, for small-scale production in Q3

Visit: http://www.tdii.com