We fabricated 40 nm-thick cobalt silicide (CoSi2) as a buffer layer, on p-type Si(100) and Si(111) substrates to
investigate the possibility of GaN epitaxial growth on CoSi2/Si substrates. We deposited GaN using a HVPE (hydride vapor
phase epitaxy) with two processes of process I (850
o
C-12 minutes + 1080
o
C-30 minutes) and process II (557
o
C-5 minutes +
900
o
C-5 minutes) on CoSi2/Si substrates. An optical microscopy, FE-SEM, AFM, and HR-XRD (high resolution X-ray diffractometer)
were employed to determine the GaN epitaxy. In case of process I, it showed no GaN epitaxial growth.
However, in process II, it showed that GaN epitaxial growth occurred. Especially, in process II, GaN layer showed selfaligned
substrate separation from silicon substrate. Through XRD ω-scan of GaN <0002> direction, we confirmed that the
combination of cobalt silicide and Si(100) as a buffer and HVPE at low temperature (process II) was helpful for GaN
epitaxy growth.