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

Abstract

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(CH 3 ) 3 and PH x radicals (PH 3 /H 2 plasmas), and (c) deposition of InN on sapphire from In(CH 3 ) 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°C and 7 min of H atoms exposure. The growth of InP epilayers with PH 3 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.