Growth of GaN
on nano-crystalline diamond substrates
G.W.G. van Dreumela, J.G. Buijnsters, T. Bohnen, J.J. ter Meulen,
P.R. Hageman, W.J.P. van Enckevort and E. Vlieg,
Abstract
In this study GaN has been grown on nano-crystalline diamond substrates
utilizing metal-organic chemical vapour deposition (MOCVD). It is shown
that the growth of closed GaN films onto synthetic diamond substrates
is feasible, when applying the correct buffer layer and growth
parameters. XRD measurements showed that the GaN formed is of wurzite
structure and polycrystalline, but the high intensity of the (0002)
diffraction peak indicates a preferential crystallite orientation. This
preferred [0001] orientation was confirmed by SEM analysis. The optical
quality of the deposited GaN layer was investigated using
cathodoluminescence and showed a large yellow luminescence peak. This
work comprises a first step in preparing heterogeneous layers and GaN
devices with a diamond heat sink as a substrate, facilitating the
thermal management of these devices.