On the use of remote RF plasma source to enhance III-V MOCVD technology

A remote RF (13.56 MHz) plasma source, assembled on a metalorganic chemical vapour deposition (MOCVD) system, was used to investigate the processes of (a) cleaning and passivation of InP substrates with H atoms (H-2 plasmas), (b) deposition of InP epilayers from In(CH3)(3) and PHx radicals (PH3/H-2 plasmas), and (c) deposition of InN on sapphire from In(CH3)(3) and N atoms (N-2-H-2-Ar plasmas). From kinetic and spectroscopic ellipsometric in situ analysis, the removal of native oxide from InP surface was found to be complete, without surface damage (phosphorus depletion), at 230 degrees C and 7 min of H atoms exposure. The growth of InP epilayers with PH3 plasma pre-activation was successful (stoichiometric InP) even at low V/III ratio. During InN growth, the use of optical emission spectroscopy (OES) and of in situ ellipsometry (SE) was determinant for the process control.