title: Damage evaluation in graphene underlying atomic layer deposition dielectrics.
abstract: Based on micro-Raman spectroscopy (μRS) and X-ray photoelectron spectroscopy (XPS), we study the structural damage incurred in monolayer (1L) and few-layer (FL) graphene subjected to atomic-layer deposition of HfO2 and Al2O3 upon different oxygen plasma power levels. We evaluate the damage level and the influence of the HfO2 thickness on graphene. The results indicate that in the case of Al2O3/graphene, whether 1L or FL graphene is strongly damaged under our process conditions. For the case of HfO2/graphene, μRS analysis clearly shows that FL graphene is less disordered than 1L graphene. In addition, the damage levels in FL graphene decrease with the number of layers. Moreover, the FL graphene damage is inversely proportional to the thickness of HfO2 film. Particularly, the bottom layer of twisted bilayer (t-2L) has the salient features of 1L graphene. Therefore, FL graphene allows for controlling/limiting the degree of defect during the PE-ALD HfO2 of dielectrics and could be a good starting material for building field effect transistors, sensors, touch screens and solar cells. Besides, the formation of Hf-C bonds may favor growing high-quality and uniform-coverage dielectric. HfO2 could be a suitable high-K gate dielectric with a scaling capability down to sub-5-nm for graphene-based transistors.
authors: ICTEAM Institute, Université catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium.
authors: Xiaohui
authors: X
authors: Tang
authors: Research Group on Carbon Nanostructures (CARBONNAGe), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.|Department of Physics, Research Center in Physics of Matter and Radiation (PMR), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
authors: Nicolas
authors: N
authors: Reckinger
authors: ICTEAM Institute, Université catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium.
authors: Olivier
authors: O
authors: Poncelet
authors: Department of Physics, Research Center in Physics of Matter and Radiation (PMR), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
authors: Pierre
authors: P
authors: Louette
authors: ICTEAM Institute, Université catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium.
authors: Ferran
authors: F
authors: Ureña
authors: Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.|Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve, Belgium.
authors: Hosni
authors: H
authors: Idrissi
authors: Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors: Stuart
authors: S
authors: Turner
authors: NAPS/IMCN, Université catholique de Louvain, 2 Chemin du Cyclotron, 1348 Louvain-la- Neuve, Belgium.
authors: Damien
authors: D
authors: Cabosart
authors: Research Group on Carbon Nanostructures (CARBONNAGe), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.|Department of Physics, Research Center in Physics of Matter and Radiation (PMR), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
authors: Jean-François
authors: JF
authors: Colomer
authors: ICTEAM Institute, Université catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium.
authors: Jean-Pierre
authors: JP
authors: Raskin
authors: NAPS/IMCN, Université catholique de Louvain, 2 Chemin du Cyclotron, 1348 Louvain-la- Neuve, Belgium.
authors: Benoit
authors: B
authors: Hackens
authors: ICTEAM Institute, Université catholique de Louvain, Place du Levant 3, 1348 Louvain-la-Neuve, Belgium.
authors: Laurent A
authors: LA
authors: Francis