Modification of MIS Devices by Irradiation and High-Field Electron Injection Treatments

Methods to modify gate dielectrics of MIS structures by irradiation treatments and high-field electron injection into dielectric are considered. In addition, distinctive features of these methods used to correct parameters of MIS devices are studied. It was found out that negative charge, accumulating in the thin film of phosphosilicate glass (PSG) of the MIS structure having a two-layer gate dielectric SiO_2-PSG under the high-field injection or during the irradiation treatment can be used to correct the threshold voltage to improve the charge stability and raise the voltage of breakdown for the MIS devices. It is proved that the density of electron traps rises with the increasing thickness of the PSG film. In this paper a method to modify electrophysical characteristics of MIS structures by the high-field tunnel injection of electrons into the gate dielectric under the mode of controlled current stress is proposed. The method allows to monitor changing of MIS structure parameters directly during the modification process.