Improvement in the electrical properties of thin gate oxides by chemical-assisted electron stressing followed by annealing (CAESA)

A novel technique called chemical-assisted electron stressing followed by annealing (CAESA) is proposed to improve a thin gate oxide film's quality, After conventional oxide growth, the wafer was put into diluted HF solution (0.245%) and was current stressed in liquid with Si substrate biased negatively, It is believed the stressing current will find the local weak spots and damage them by the energy release of electrons, With additional high-temperature rapid thermal annealing (RTA), the damaged spots will be annealed out. It is found that the charge-to-breakdown Q/sub bd/ of oxide can be significantly improved by the CAESA process,.