Influence of WSi2 polysilicide gate process on integrity and reliability of gate and tunnel oxides

Abstract The deposition of polysilicide layers can contribute to the generation of defects in gate or tunnel oxides which can have a detrimental influence on the reliability of non-volatile memories. Two processes of WSi 2 deposition were studied. The charge and the interface state densities created by Fowler-Nordheim electron injections in the gate oxide, the charge before intrinsic breakdown and the programming window degradation after erase/write cycles of EEPROM were compared. The three types of tests are well correlated.