September 14, 2007 16:39 ET

TDI Introduces Nonpolar GaN Substrates

SILVER SPRING, MD--(Marketwire - September 14, 2007) - Technologies and Devices International, Inc., a privately held Maryland corporation (TDI), today announced a significant step in the development of advanced substrate materials for high brightness, high efficiency GaN-based light emitting diodes (LEDs) by demonstrating a new product prototype of 2-inch nonpolar a-plane GaN substrates. Novel 2-inch diameter a-plane GaN-on-sapphire substrates will be featured at the 7th International Conference on Nitride Semiconductors in Las Vegas, from September 17 through September 20, 2007. Test quantities of the new substrates are available for shipment.

Nonpolar GaN substrates are needed to fabricate GaN light emitting devices, including LEDs and laser diodes, with improved efficiency and output power, especially for devices emitting in green spectrum region. Currently most commercial GaN-based devices are produced on crystalline substrates with surface crystallographic orientations parallel to c-crystallographic plane called "polar surfaces." Due to specific physical properties of the GaN material system, this crystallographic plane is not optimal for optoelectronic applications due to piezoelectric polarization effects. It has been demonstrated by a number of research teams that GaN devices fabricated on other crystallographic (nonpolar or semipolar) surfaces such as a-plane, have great promise for device improvement.

TDI has developed a process to deposit a-plane GaN layers with improved surface and crystal quality on sapphire to produce commercial nonpolar GaN substrate materials. The product consists of a GaN layer several microns thick with a-plane orientation deposited on r-plane sapphire substrates. GaN deposition is done by company's proprietary hydride vapor phase epitaxial (HVPE) process and equipment.

"TDI is manufacturing and supplying a variety of nitride products including GaN, AlGaN, AlN, InN, and InGaN template substrates," said Vladimir Dmitriev, President and CEO of TDI. "Governed by a strong demand from TDI customers for nonpolar GaN substrates, we have introduced a novel HVPE process to fabricate a-plane GaN materials with substantially improved properties while at the same time avoiding expensive technological steps to keep low production cost. This allows us to offer c-plane and a-plane GaN products in commercial quantities at similar price levels. The product is now available in test quantities in two configurations (i) with GaN as-grown surface and (ii) with GaN epi ready polished surface. Full-scale production of a-plane GaN template substrates is scheduled for the first quarter of 2008."

"Deposition of high quality GaN materials with nonpolar crystallographic orientations is technically challenging. Significant process improvements at TDI now allow us to provide our customers with a-plane GaN substrates, which will make development and commercialization work on nonpolar GaN light emitting devices much easier," added Alexander Usikov, R&D Director at the company. "We are working on the next generation of nonpolar substrates and device structures, and recently have succeeded in the fabrication of R&D samples of a-plane and m-plane InGaN materials on nonpolar GaN templates and bulk GaN substrates. These results will be presented at the International Conference on Nitride Semiconductors in Las Vegas next week."

Optoelectronic and electronic devices based on Group III Nitride materials (GaN, AlN, InN) are the subject of intense development for various applications including solid state lighting, bio and chemical detection systems, environmental, communication and military equipment. The GaN-based market is projected to reach $5B in 2007 and exceed $7B in 2009. Substrate market for GaN devices is forecast to excess of $1B in three-four years.

About TDI

The company is a privately owned developer and manufacturer of novel compound semiconductors including GaN, AlN, AlGaN, InN, and InGaN. TDI has developed and commercialized a variety of compound semiconductor materials, primarily for applications in solid state lighting, short wavelength optoelectronics and RF power electronics. For novel development results and TDI's product list please visit

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