Nucleation of GaN crystallites by sublimation method on sapphire (0001
), scratched sapphire (0001), SiO2, on Si (111), and metalorganic chem
ical vapor deposition(MOCVD)-GaN/sapphire (0001) was investigated. The
density of the nuclei on SiO2 and Si (111) was estimated to be 6 x 10
(3)/cm(2). On the other hand, a continuous film rather than discrete c
rystallites tvas obtained on both the MOCVD-GaN and the scratched sapp
hire. Growth nucleation control was performed by partly covering the M
OCVD-GaN or scratched sapphire (0001) with SiO2. As a result, hexagona
l columns about 200 mu m in diameter and 200 mu m high were selectivel
y and uniformly grown at the window sites. The diameter of each hexago
nal column nas much larger than the width of each window. This method
can be used for device processing utilizing the crystallites.