Cheap GaN
Kirt's Cogitations™ #78

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Cheap GaN

Scientists at Sumitomo Electric Industries has figured out how to grow gallium nitride (GaN) crystals on inexpensive GaN substrates rather than on sapphire or silicon carbide substrates. Lattice dislocations (imperfect matching between GaN and the sapphire or SiC) cause inefficiencies in the operation of the blue laser diode applications that GaN is predominantly used for. GaN crystals grown on GaN substrates are nearly perfect. Still, GaN is expensive at around $10k for a 2" wafer compared to around $200 for a Si wafer 4-6 times as large. Roughly 1000 diodes can be produced from a 2" wafer, making the die cost alone about $10. Blue lasers can yield a storage capacity of 27 GB on a standard DVD (a 6x increase). Don't expect to find one of these babies in the next Sunday sale flyer PC system because the first production DVD drives are now selling for about $3800 from Sony.