ABSTRACT
This chapter discusses the electrical characteristics and some reliability issues of complementary metal-oxide-semiconductor (CMOS) devices using high-dielectric constant (high-k) as their gate dielectric films. Threshold voltage control has become one of the major concerns for the actual application of a high-k gate dielectric in CMOS devices. Hot carrier reliability was recognized as a serious issue, since the channel electric field near the drain region is significantly larger than the critical field for impact ionization in deep submicron devices. Negative bias temperature instability in p-channel transistors is another major concern. Hafnium-based dielectric films have already been used for production in the state-of-the-art logic circuits, most of the device characteristics of the metal oxide semiconductor transistors—such as the channel mobility and then the ON current, the subthreshold slope, and thus the OFF current—have been greatly deteriorated by using the high-k gate dielectrics.
