Taeho Kang, Joonho Park, Hanggyo Jung, Haeju Choi, Sang-Min Lee, Nayeong Lee, Ryong-Gyu Lee, Gahye Kim, Seung-Hwan Kim, Hyung-Jun Kim, Cheol-Woong Yang, Jongwook Jeon, Yong-Hoon Kim, Sungjoo Lee
Herein, we report a high-quality gate stack (native HfO2 formed on 2D HfSe2 ) fabricated via plasma oxidation, realizing an atomically sharp interface with a suppressed interface trap density (Dit ∼ 5×1010 cm-2 eV-1 ). The chemically converted HfO2 exhibits dielectric constant, κ ∼ 23, resulting in low gate leakage current (∼10-3 A/cm2 ) at EOT ∼0.5 nm. Density functional calculations indicated that the atomistic mechanism for achieving a high-quality interface is the possibility of O atoms replacing the Se atoms of the interfacial HfSe2 layer without a substitution energy barrier, allowing layer-by-layer oxidation to proceed...
March 26, 2024: Advanced Materials