Auger electron spectroscopy (AES) was used to investigate the processes taking place during the initial stages of InP(100) surfaces nitridation. This AES study combined with electrical measurements (intensity-voltage) shows that the processes greatly differ depending on the nitridation angles. Results show that with grazing angle for nitrogen flow, the nitridation process is more efficient. Results obtained with AES spectra are coherent with electrical measurements: Hg/InN/InP(100) Schottky diodes present different electrical characteristics for the grazing and normal flow. The passivation effect of the nitride layers depends on the incident nitrogen angle flow. (C) 2004 Elsevier B.V. All rights reserved.