These original Kirt's Cogitations™ may be reproduced
(no more than 5, please) provided proper credit is given to me, Kirt Blattenberger.
here to return to the Table of Contents.
Cog·i·ta·tion [koj-i-tey'-shun] – noun: Concerted
reflection; meditation; contemplation.
Kirt [kert] – proper noun: RF Cafe webmaster.
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.