Real time ellipsometry for monitoring plasma-assisted epitaxial growth of GaN

GaN is grown on Si-face 4H-SiC(0 0 0 1) substrates using remote plasma-assisted methods including metalorganic chemical vapour deposition (RP-MOCVD) and molecular beam epitaxy (MBE). Real time spectroscopic ellipsometry is used for monitoring all the steps of substrate pretreatments and the heteroepitaxial growth of GaN on SiC. Our characterization emphasis is on understanding the nucleation mechanism and the GaN growth mode, which depend on the SiC surface preparation