Blue LED and LD have attracted much attention of many device and material researchers. The GaN crystals are usually grown on Al2O3 crystals, so the device structure is complicated and cleavage face is not apparent. We have studied the growth of GaN on Si substrates by using BP as a buffer crystal. The objectives are
1, to make low cost devices,
2, to grow cubic type GaN on Si to fabricate insensitive devices for stress during laser action,
3, to fabricate OEIC devices in the near future.
We have grown GaN/BP on 2inchs in diameter Si (100) substrates by using MOVPE machine. The BP crystal and GaN crystals are epitaxially grown on Si. The substrates were markedly flat by
the role of buffer crystal. If the buffer was not sufficient , the stress during crystal growth was too high to curve the substrates in the presence of many slips. The photoluminescence signal demonstrated the grown GaN crystals was mainly cubic type. The crystal structures were strongly depended on the growing temperature without any irradiation. The cubic type has a tendency to be grown with low temperature growth. At the first stage BP layers has a little bit inclined around 5 degrees to Si (100). The electrical conductivity of BP is widely variable with the gas ratio and the temperature.
As an electron devices GaN FET is possible to grow by using AlN as an insulating layers. The combined devices will be the fundamental OEIC. At the meeting, the device structures and the growth will be shown.