SEI To Produce First 2-inch Semi-Polar and Non-Polar GaN Substrates
Sumitomo Electric Industries has developed production technology which will enable large scale production of 2-inch diameter semipolar/nonpolar GaN (gallium nitride) substrates for green lasers.
Following its successful development of green semiconductor lasers in 2009, Sumitomo Electric has been developing manufacturing technology for semipolar and nonpolar GaN substrates. These materials will improve the performance of green semiconductor lasers and white LEDs (light emitting diodes). These efforts have resulted in the development of manufacturing technologies that inhibit piezoelectric effects on polarized substrates, improving device luminous efficiency.
In general, semipolar and nonpolar GaN substrates are manufactured by vertically or diagonally slicing GaN crystals along the c-plane. However, this method results in relatively small crystals (rectangular crystals with dimensions on the order of several millimeters). The size of these materials has been a major obstacle to increasing the production scale of higher efficiency LED devices.
To overcome this limitation, Sumitomo Electric has developed H-VPE (hydride vapor phase epitaxy) manufacturing technology for large scale production of 2-inch substrates. The substrates produced by this newly developed technology exhibit a dislocation density on the order of 105, comparable to that of the c-plane substrates now in use.