title: Mesostructured HfxAlyO2 Thin Films as Reliable and Robust Gate Dielectrics with Tunable Dielectric Constants for High-Performance Graphene-Based Transistors.
abstract: We introduce a reliable and robust gate dielectric material with tunable dielectric constants based on a mesostructured HfxAlyO2 film. The ultrathin mesostructured HfxAlyO2 film is deposited on graphene via a physisorbed-precursor-assisted atomic layer deposition process and consists of an intermediate state with small crystallized parts in an amorphous matrix. Crystal phase engineering using Al dopant is employed to achieve HfO2 phase transitions, which produce the crystallized part of the mesostructured HfxAlyO2 film. The effects of various Al doping concentrations are examined, and an enhanced dielectric constant of ∼25 is obtained. Further, the leakage current is suppressed (∼10(-8) A/cm(2)) and the dielectric breakdown properties are enhanced (breakdown field: ∼7 MV/cm) by the partially remaining amorphous matrix. We believe that this contribution is theoretically and practically relevant because excellent gate dielectric performance is obtained. In addition, an array of top-gated metal-insulator-graphene field-effect transistors is fabricated on a 6 in. wafer, yielding a capacitance equivalent oxide thickness of less than 1 nm (0.78 nm). This low capacitance equivalent oxide thickness has important implications for the incorporation of graphene into high-performance silicon-based nanoelectronics.
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.|School of Electrical Engineering, Korea University , Seoul 136-713, Republic of Korea.
authors.forename: Yunseong
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.
authors.forename: Woojin
authors.initials: W
authors.lastname: Jeon
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.
authors.forename: Yeonchoo
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.
authors.forename: Min-Hyun
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.
authors.forename: Seong-Jun
authors.initials: SJ
authors.lastname: Jeong
authors.affiliation: School of Electrical Engineering, Korea University , Seoul 136-713, Republic of Korea.
authors.forename: Jongsun
authors.initials: J
authors.lastname: Park
authors.affiliation: Device Lab., Device & System Research Center, Samsung Advanced Institute of Technology , Suwon 16678, Republic of Korea.
authors.forename: Seongjun
authors.initials: S
authors.lastname: Park
keywords: atomic layer deposition; capacitance equivalent oxide thickness; graphene; mesostructure; phase transition engineering