We have analyzed the influence of the dielectric composition and the post deposition rapid thermal annealing (RTA) treatment on the electrical characteristics of electron-cyclotron-resonance plasma-deposited SiNx:H/n and p-In0.53Ga0.47As interfaces. The devices are characterized by means of capacitance-voltage (C-V), deep-level transient spectroscopy (DLTS) and conductance transient analyses. Our results show that a simple cleaning step of the semiconductor surface prior to insulator deposition, and a post deposition RTA process are sufficient to obtain good-quality structures, the n-type being better than the p-type. In both cases, we conclude that a dielectric composition of x = 1.50 seems to be the best choice, and that the most adequate RTA temperature is between 500 degreesC and 600 degreesC
