A joint research between Semiconductors Laboratory
of RIKEN(the Institute of Physical and Chemical Research) and Research
Institute for Electrical Science of Hokkaido University has succeeded
in developing a simple in-situ production technology of gallium
nitride(GaN) crystalline thin films with low dislocation density.The
GaN films produced by this technology will be used as base substrates
for the production of the high-quality III−nitride optoelectronic
devices. This technology will lead to low-cost and high-performance
violet laser diodes that will be used for reading and writing the
next-generation digital versatile disks(DVDs).
The III−nitride semiconductors such as GaN, aluminium nitride(AlN)
and indium nitoride(InN), emit light in green, blue and ultraviolet
regions. Devices based on these semiconductors are expected to be
used in various next-generation electronic machines and equipment.
In general sapphire and silicon carbide have been used as base substrates
for their grouth, since there are no other proper substrates. However,
a great number of crystal defects (threading dislocations) are induced
due to the large difference between the lattice constants of the
III−nitride crystalline layers and the substrates.
The new technology has been developed to solve this serious problem.
Only an in-situ process is rerquired and any complicated treatments
outside of the crystal growth machine are unnecessary. The dislocation
density is reduced to less than 1% from that of the convensional
III−nitride films. It is promised that high-quality III−nitride
layers would be grown on the GaN films with the reduced dislocation
density.
(For further information, contact the Publicity Section, RIKEN:
phone 048-467-9271)
(Source:STA TODAY April 2000) |
