A review of rare-earth oxide films as high k dielectrics in MOS devices — Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

Recently, rare-earth oxide films have attracted more and more attention as gate dielectrics in metal-oxide-semiconductor (MOS) devices, showing the advantages of high dielectric constant (k value), large band gap (Eg) and outstanding physical and chemical stability in contact with silicon substrates. This paper reviews the recent development of rare earth oxide-based gate dielectric films. Aiming at the problem that k value of rare earth oxides (REOs) is generally inversely proportional to the band gap value, one of the biggest technical obstacles of high k films, we reviewed three strategies reported in recent papers, namely doping modification, nitriding treatment and multilayer composite, which can provide some insights for long-term development of MOS devices in integrated circuit (IC).