GaN epitaxy growth by low temperature HYPE on $CoSi_2$ buffer/Si substrates

We fabricated 40 nm-thick cobalt silicide () as a buffer layer, on p-type Si(100) and Si(111) substrates to investigate the possibility of GaN epitaxial growth on /Si substrates. We deposited GaN using a HVPE (hydride vapor phase epitaxy) with two processes of process I (-12 minutes + -30 minutes) and process II (-5 minutes + -5 minutes) on /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 -scan of GaN 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.