Sumitomo Electric produces GaN wafers in volume
Sumitomo Electric expects to produce the substrates, each of which can be used to make 10,000 lasers, at an initial rate of 200 units per month. It plans to boost output to 500 units per month in October and market the substrates to laser manufacturers.
Other Japanese wafer manufacturers, including Furukawa and Hitachi Cable, have also recently indicated that they will start to produce GaN substrates (see Hitachi Cable to produce gallium nitride substrates).
Sumitomo Electric first announced the development of GaN substrates in 2000 (see Development of single crystal gallium nitride).
The company established its own unique crystal growth process, named DEEP or Dislocation Elimination by Epitaxial growth with inverse-pyramidal Pits. The technique reduces dislocations by forming inverse-pyramidal pits on the surface of the grown crystal (see SEI News - GaN substrate).
Low dislocation-density areas of the GaN substrates fabricated using the DEEP technique have a dislocation density of around 106 /cm2. This is about 104 times less than the dislocation density of conventional GaN epitaxial layers on sapphire substrates.
Sumitomo Electric is also involved in a different approach to wide bandgap optoelectronic components. The company recently formed a joint venture, Supra Opto, with Procomp Informatics to manufacture ZnSe white LEDs (see Joint venture will produce ZnSe white LEDs).
