Oxygen‐Scavenging Effects of Added Ti Layer in the TiN Gate of Metal‐Ferroelectric‐Insulator‐Semiconductor Capacitor with Al‐Doped HfO<sub>2</sub> Ferroelectric Film
Yong Bin Lee, Beom Yong Kim, Hyeon Woo Park, Suk Hyun Lee, Minsik Oh, Seung Kyu Ryoo, In Soo Lee, Seungyong Byun, Doosup Shim, Jae Hoon Lee, Hani Kim, Kyung Do Kim, Min Hyuk Park, Cheol Seong Hwang
Abstract
Abstract Ti layer inserted in the TiN gate electrode effectively scavenges the oxygen in the low‐ k interfacial SiO 2 of the metal–ferroelectric–insulator–semiconductor (MFIS) capacitors with the ferroelectric Al‐doped HfO 2 (HAO) thin film. The scavenging effect increases remanent polarization (P r ) and reduces coercive voltage (V c ) and capacitance equivalent thickness (CET) of the HAO films, particularly when the MFIS capacitor is annealed at 800 °C. Additionally, frequency dispersion of capacitance characteristics and interface trap density (D it ) calculations reveal that actively‐triggered oxygen‐scavenging effects also reduce defect or trap‐induced degradation. The Ti‐inserted MFIS structure exhibits fatigue‐free endurance and relatively low leakage current characteristics as compared to a structure without the Ti scavenging layer in high annealing temperature conditions required for crystallization of the HAO ferroelectric films.