Monitoring of HyGaNx and Ga in OMCVD of GaN, using molecular beam quadrupole and REMPI-TOF mass spectrometry

A new route in organometallic chemical vapour deposition (OMCVD) of GaN lay ers is the single-source precursor method. Molecular beam sampling using qu adrupole mass spectrometry and resonance-enhanced multiphoton ionisation ti me-of-flight mass spectrometry (REMPI-TOF-MS) has been used to show that ga llium atoms and gallium-nitrogen compounds, like HGaNx (n = 2-6) and GaNx ( x = 2-6), appear in the boundary layer of a sapphire substrate during therm al decomposition of (N-3)(2)G[CH2CH2CH2N(CH3)(2)] in the temperature range 400-1000 K, The temperature dependence of the species is shown to be direct ly correlated with the growth rate of GaN layers. (C) 1999 Elsevier Science B.V. All rights reserved.