The deal gives Sony access to Nichia's patents and know-how, and gives Nichia the strongest partner in the laser business. Nichia is virtually the sole supplier of gallium nitride lasers, while Sony is a major vendor of lasers for CD and DVD systems, with a production capacity of 16.5 million units a month. Another 5 million units of red lasers for DVD systems will be added when a new fab at the site of Shiraishi Semiconductor, in Fukushima Prefecture, begins operation next summer.

Quiet collaboration

The two companies began their collaboration in June but waited until Wednesday (Dec. 18) to disclose it when it became clear that "we will be able to develop a violet laser for volume production by next spring," said a Nichia spokesman.

"We believe that Nichia and Sony are the most advanced companies in violet-laser development. By making use of each other's patents, we can introduce high-performance lasers in a short time," he said.

Nichia is already selling violet lasers and sources said Sony is close to marketing them as well. At the International Symposium on Compound Semiconductors in October, Sony engineers reported development of lasers that are estimated to operate 10,000 hours under 50-milliwatt output power at 70°C, using an epitaxial lateral overgrown substrate on top of a sapphire substrate.

Using a GaN substrate that recently became available from Sumitomo Electric Industries Ltd. improves that performance, Sony engineers said, boosting the lifetime to 100,000 hours with 30-mW output power at 60°C.

Nichia has the two-flow MOCVD system, the key technology needed to generate a GaN crystal layer on a sapphire substrate with few defects, despite the big difference in lattice constants between GaN and sapphire. Sony once used a raised-pressure MOCVD method to grow the GaN layer on sapphire. Neither company would say which technologies, including the MOCVD technique, would be shared under the collaboration.

Sony is one of the leading promoters of the Blu-ray Disk, a writable optical-disk system that uses a violet laser to realize a DVD capacity of 23 to 27 Gbytes per side. Sony sets the target specifications for Blu-ray Disk lasers at 405 nanometers, with output power of 100 mW, to write data to two-layer disks with reliability of more than 5,000 hours.

"The first target for the new alliance is to develop a high-power 405-nm laser for the Blue-ray Disk system," said a Sony spokesman.

The companies will each manufacture and sell the products resulting from the joint development effort, and they will be the second source for each other's products.

Laser field

In preparation for the coming era of blue-laser optical disks, Sharp Corp., another leading semiconductor laser supplier, has disclosed plans to begin volume production of violet lasers at the end of next year, at a new fab now under construction in Mihara, Japan. Sharp's prototype has 30-mW output power with an aspect ratio of 2.0 using a GaN substrate.

Rohm Co. Ltd. is developing a silicon carbide-based laser with Cree Inc., and Toyoda Gosei Co. Ltd. has also said it is working on next-generation lasers.