February 20, 2007 – Showa Denko KK says it has developed a new hybrid process for making compound semiconductors based on gallium nitride (GaN) and other nitrides, using a combination of conventional metal organic chemical vapor deposition (MOCVD) and a proprietary plasma-assisted physical deposition.
The new process technology enables production of 4-in. epitaxial wafers with higher quality than is achievable with MOCVD alone. Showa Denko claims to have made blue LEDs using the hybrid process “with the highest-level brightness on the market today,” and to start shipping commercially “within this year.”
Analyzed via an X-ray rocking curve (XRC) method, the layer of single crystal nitride formed on a sapphire substrate produced by the PPD process shows significant improvement in crystal quality over a similar product produced by the MOCVD process, the company claims (see figure below).
A new facility will be built at Showa’s site in Chiba, Japan, to produce the 4-in. epi wafers based on the new process technology, and the company will more than triple its output of blue LEDs from 30 million units to 100 million units/month by year’s end.