High-k gate dielectrics has become part of the mainstream CMOS technology, including advanced FinFET devices. We have discussed the historical evolution of this high-k gate dielectric through scientific and technological challenges over many decades until it was introduced into 45 nm CMOS technology in 2007 by replacing SiO2. Interface and dipole issues were somewhat resolved through scientific understanding and technological innovation. Thanks to the step coverage advantage of atomic layer deposition process, high-k was easily migrated to FinFET technology. Reliability of devices with high-k was a significant problem in the beginning but over time it has been improved significantly. Use of high-k on new semiconductor substrates such as III-V, Ge and 2D materials is currently being investigated but faces many challenges. Recent discovery of ferroelectric properties of HfO2 makes it viable for more potential applications.
All Science Journal Classification (ASJC) codes