CHARGE-PUMPING ANALYSIS OF RADIATION EFFECTS IN LOCOS PARASITIC TRANSISTORS

We have performed current-voltage and charge pumping measurements on L OGOS parasitic transistors submitted to x-ray irradiation. The electri cal behavior and the charge pumping response of these non-planar struc tures have been analyzed by two-dimensional computer simulations. We r eport how this experimental approach allows us to obtain quantitative information about oxide charge and interface trap densities in differe nt parts of the complete structure. Our results show a maximum of oxid e charge trapping and interface trap buildup in the bird's beak region s after irradiation. The generation of radiation-induced interface and border traps along the LOGOS SiO2/Si interface is discussed, in terms of trap density and frequency response.