  The nitridation of InP(1 0 0) surfaces has been studied using synchrotron
radiation photoemission. The samples were chemically cleaned and then ion
bombarded, which cleaned the surface and also induced the formation of metallic
indium droplets. The nitridation with a Glow Discharge Cell (GDS) produced
indium nitride by reaction with these indium clusters. We used the In 4d and P
2p core levels to monitor the chemical state of the surface and the coverage of
the species present. We observed the creation of In-N and P-N bonds while the
In-In metallic bonds decrease which confirm the reaction between indium
clusters and nitrogen species. A theoretical model based on stacked layers
allows us to assert that almost two monolayers of indium nitride are produced.
The effect of annealing on the nitridated layers at 450 $^\circ$C has also been
analysed. It appears that this system is stable up to this temperature, well
above the congruent evaporation temperature (370 $^\circ$C) of clean InP(1 0
0): no increase of metallic indium bonds due to decomposition of the substrate
is detected as shown in previous works [L. Bideux, Y. Ould-Metidji, B. Gruzza,
V. Matolin, Surf. Interface Anal. 34 (2002) 712] studying the InP(1 0 0)
surfaces.
