When a MOS structure (Metal Oxide Semiconductor) is subjected to an external perturbation, defects are generated in the oxide and at the oxide-semiconductor interface. If one can easily measure distinctively the interface states and the oxides defects with the electrical method, it is difficult to separate between the different kinds of oxides defects and to obtain a microscopic nature of these defects. In this work, we are using a procedure that we have defined and which derives from a capacitive method known under the name of Jenq method in order to get further information on the proceeding...