Aug 30 2007
Technologies and Devices International, Inc., (TDI), the leading developer and supplier of compound nitride semiconductor materials, today announced another major breakthrough in Gallium Nitride (GaN) compound semiconductor material technology by fabrication of the first epitaxial structures for blue (450 – 490 nm) and green (490 – 510 nm) light emitting diodes (LEDs) grown by hydride vapor phase epitaxy (HVPE).
GaN is the compound semiconductor material used for the fabrication of blue spectrum (blue, green, ultra violet (UV) and white) LEDs, laser diodes (LDs) and high-frequency/high-power transistors. The GaN-based market is projected to reach $5B in 2007 and exceed $7B in 2009.
“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,” said Vladimir Dmitriev, president and CEO of TDI. “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 efficient 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. Now, with TDI’s novel HVPE process and equipment, these issues are solved and the first all-HVPE LEDs emitting in blue and green spectrum region have been developed. Demonstration of these devices by HVPE method is an important step for expansion of low cost light emitting devices for solid state lighting applications.”
“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,” added Dr. Alexander Usikov, R&D Director at TDI. “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 wide range of deposition rates. Development of InGaN materials and quantum well structures allowed TDI to fabricate blue and green LEDs using the HVPE method, for the first time. We are working to increase InGaN contents in the LED structures toward fabrication of yellow and potentially red light emitting devices”.