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.