title: Atomic layer deposition of dielectrics on graphene using reversibly physisorbed ozone.
abstract: Integration of graphene field-effect transistors (GFETs) requires the ability to grow or deposit high-quality, ultrathin dielectric insulators on graphene to modulate the channel potential. Here, we study a novel and facile approach based on atomic layer deposition through ozone functionalization to deposit high-κ dielectrics (such as Al(2)O(3)) without breaking vacuum. The underlying mechanisms of functionalization have been studied theoretically using ab initio calculations and experimentally using in situ monitoring of transport properties. It is found that ozone molecules are physisorbed on the surface of graphene, which act as nucleation sites for dielectric deposition. The physisorbed ozone molecules eventually react with the metal precursor, trimethylaluminum to form Al(2)O(3). Additionally, we successfully demonstrate the performance of dual-gated GFETs with Al(2)O(3) of sub-5 nm physical thickness as a gate dielectric. Back-gated GFETs with mobilities of ~19,000 cm(2)/(V·s) are also achieved after Al(2)O(3) deposition. These results indicate that ozone functionalization is a promising pathway to achieve scaled gate dielectrics on graphene without leaving a residual nucleation layer.
authors.affiliation: Department of Materials Science and Engineering, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA.
authors.forename: Srikar
authors.initials: S
authors.lastname: Jandhyala
authors.forename: Greg
authors.initials: G
authors.lastname: Mordi
authors.forename: Bongki
authors.initials: B
authors.lastname: Lee
authors.forename: Geunsik
authors.initials: G
authors.lastname: Lee
authors.forename: Carlo
authors.initials: C
authors.lastname: Floresca
authors.forename: Pil-Ryung
authors.initials: PR
authors.lastname: Cha
authors.forename: Jinho
authors.initials: J
authors.lastname: Ahn
authors.forename: Robert M
authors.initials: RM
authors.lastname: Wallace
authors.forename: Yves J
authors.initials: YJ
authors.lastname: Chabal
authors.forename: Moon J
authors.initials: MJ
authors.lastname: Kim
authors.forename: Luigi
authors.initials: L
authors.lastname: Colombo
authors.forename: Kyeongjae
authors.initials: K
authors.lastname: Cho
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim