Observation of quantum-Hall effect in gated epitaxial graphene grown on SiC (0001)

Abstract

Epitaxial graphene films examined were formed on the Si-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. A high-k gate stack on the epitaxial graphene was realized by inserting a fully oxidized nanometer thin aluminum film as a seeding layer, followed by an atomic-layer deposition process. The electrical properties of epitaxial graphene films are retained after gate stack formation without significant degradation. At low temperatures, the quantum-Hall effect in Hall resistance is observed along with pronounced Shubnikov-de Haas oscillations in diagonal magneto-resistance of gated epitaxial graphene on SiC (0001).

Scanning tunneling microscope study of striated carbon ridges in few-layer epitaxial graphene formed on 4H-silicon carbide (0001¯)

“…15,17,18 This study focuses on FLG grown on the C-face of SiC because of the higher mobilities that have been reported. 13,14 The features reported below were consistently reproduced between the three samples. 19,20 The 1D ridges, found on all samples of FLG grown for this study, formed interconnected networks that divided the atomically flat graphene overlayer into large tilelike regions.…”

“…12 Interestingly, electron mobilities reported on FLG grown on the C-face of SiC seem to be considerably higher than mobilities measured on the Si-face. 13,14 While the origin of this difference is not yet clear, a distinguishing dissimilarity between C-face and Siface FLG is the presence of a carbon ridge network that develops on the C-face material.…”

Statistical Study of Deep Submicron Dual-Gated Field-Effect Transistors on Monolayer Chemical Vapor Deposition Molybdenum Disulfide Films

“…After the lift-off process, a 0.8-1 nm Al seeding layer was deposited at the rate of 0.1 Å/s on the whole sample to facilitate dielectric growth. [22][23][24] The samples were then aged overnight in atmosphere to secure a complete oxidation of ~1 nm Al2O3 as the seeding layer. After that, a 15 nm Al2O3 was deposited by atomic layer deposition (ALD) at 200 ºC using trimethylaluminum (TMA) and water.…”

Multicarrier transport in epitaxial multilayer graphene

“…In particular, graphene growth is much faster on the C-face, so that at the same growth temperature, multiple layers of graphene are more readily formed on the C-face than on the Si-face substrates. Nevertheless, the conductive carbon films produced on either crystal face of SiC possess the same honeycomb lattice structure and the transport characteristics unique to graphene, such as the linear Dirac E-k spectrum [7] and the anomalous quantum Hall effect [8]. In addition, there is mounting evidence that multi-layer graphene (MLG) films grown on the C-face SiC are typically rotationally disordered with a band structure very similar to that of an individual graphene monolayer [7,[9][10].…”