Degradation mechanism of InP MOS structures on the basis of Al2O3

In this report a conclusion on causes of catastrophic degradation of InP MOS structures parameters when T_an>400°C was drawn. For these purposes CV characteristics of MOS structures, element and chemical composition of dielectric layers, and state of transitional region of Al₂O₃-InP interface were measured. It was determined that the flowing of interphase interaction at the interface is the main reason for the degradation processes. This leads to interface diffusion, disturbance of stoichiometry of InP in transitional layer, and to appearance of non-oxidized In in the bulk of Al₂O₃ film. It was shown that non-stoichiometry of deposited dielectric film, thermal decomposition of InP under this layer, penetration of O₂ through Al₂O₃ film and presence of InP native oxides at the Al₂O₃-InP interface are the stimulating factors of these degradation effects