Review and Perspective of Hf-based High-k Gate Dielectrics on Silicon

HfO2 has been recently highlighted as the most promising high-k dielectrics for the next-generation CMOS device applications due to its relatively high dielectric constant and superior thermodynamic stability from calculated Gibbs free reaction with Si. However, the high permeability to oxygen, the low crystallization temperature and the formation of the low-k interfacial layer during high temperature processing causes equivalent oxide thickness scaling and reliability concerns. Therefore, novel Hf-based high-k gate dielectrics should be studied to meet the requirements of the future advanced CMOS devices. This article provides a comprehensive view of the state-of-the-art research activities in advanced Hf-based high-k gate dielectrics, including their preparation, characterization, and potential applications in CMOS device. We begin with a survey of the requirements of high-k oxides, and then various methods developed for generating Hf-based high-k gate dielectrics. After that, more attention has been paid to the detailed discussion of on the latest development of novel Hf-based high-k gate dielectrics which have the potential for integration into a full CMOS process. Finally, we conclude this review with the perspectives and outlook on the future developments in this area. This review explores the possible influences of research breakthroughs of Hf-based gate dielectrics on the current and future applications for nano-MOSFET devices.