Highly compressively strained (GaIn)(NP) quantum wells have been grown on (10 0) GaP substrates by metal organic vapour-phase epitaxy (MOVPE). We achieve a high structural quality of the grown multiple quantum well structures for this novel, metastable material system. Competition between the group-V elements on the surface determines the N incorporation in Ga(NP) as well as (GaIn)(NP). For the ternary material system Ga(NP) the N content of the deposited layers does not depend on the growth rate in contrast to the quaternary system (GaIn)(NP), where the N incorporation is enhanced with increasing growth rate. This suggests a desorption controlled N incorporation process for the In-containing material. This is in accordance with the strong dependence of the N content in the material from the growth temperature and the In content. In addition - due to the metastability of the material systems under investigation - the maximal achievable N content in Ga(NP) and (GaIn)(NP) is limited when good crystal quality is to be retained. (C) 2004 Elsevier B.V. All rights reserved.