Effect of Fluorine on Interface Characteristics in Low-Temperature CMIS Process with HfO2 Metal Gate Stacks

In this paper, the effects of fluorine into HfO2 interface region by a low-temperature process are described. The new process for incorporating fluorine in the interface region has been optimized, and it has been found that fluorine terminates the interface defect. As a consequence, an ideal interface has been realized, which improves the negative bias temperature instability (NBTI) in metal gate electrode devices fabricated by the low-temperature process.