Hydrogen induced and plasma charging enhanced positive charge generation in gate oxides

摘要

A significant number (/spl sim/10/sup 12/ cm/sup -2/) of fixed and mobile positive charges are generated in gate oxides during forming gas (FG, 10%H/sub 2/) anneal at 450/spl deg/C. We report here for the first time that the (simulated) plasma charging enhances this generation. The generation increases with the FG anneal time and no saturation was observed. The dependence of the generation on the simulated plasma charging condition is investigated. The electrical and thermal properties of these positive charges are explored. Wherever possible, the FG anneal induced positive charges are compared with the defects responsible for irradiation and hot carrier induced degradation. Several important differences are found between them and we conclude that they have different origins.