The aim of this work is to obtain the electrical properties of a leaky 2 nm ultrathin thermally grown nitride film using the classical high frequency capacitance (C(V)) measurements, The substrate Si(100) surface cleaned in ultrahigh vacuum is nitrided in a low pressure (1 x 10(-4) mbar) of nitric oxide (NO) gas at 1050 degreesC. This film is characterised by Auger electron spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and reflection electron energy loss spectroscopy. The deposition of a self-assembled insulating monolayer of organic molecules (octadecyltrichlorosilane) on the nitride gives rise to a metal insulator semiconductor structure which permits to obtain the electrical properties of the ultrathin nitride film.