Thin native oxides with different compositions were grown on InP before metal deposition to increase the Schottky barrier height and the behavior of-the metal-oxide-InP tunnel diode. Three types of interfacial oxides were compared : they were obtained by thermal, anodic, and W-assisted oxidation, their composition being close to InPO4, In(PO3)(3), and InP0.5O3, respectively. The diode parameters (barrier height, ideality factor) were extracted from the electrical characteristics and correlated with the nature of the interfacial oxide. Particular attention was devoted to the study of diode stability under forward and reverse bias voltage. The best results were obtained with W-assisted oxides which reached a barrier height of about 0.74 eV, an ideality factor of 1.17 very high stability, and a breakdown voltage of 20 V. These characteristics meet the requirements of metal semiconductor field effect transistor realization.