title: Boosting the Boron Dopant Level in Monolayer Doping by Carboranes.
abstract: Monolayer doping (MLD) presents an alternative method to achieve silicon doping without causing crystal damage, and it has the capability of ultrashallow doping and the doping of nonplanar surfaces. MLD utilizes dopant-containing alkene molecules that form a monolayer on the silicon surface using the well-established hydrosilylation process. Here, we demonstrate that MLD can be extended to high doping levels by designing alkenes with a high content of dopant atoms. Concretely, carborane derivatives, which have 10 B atoms per molecule, were functionalized with an alkene group. MLD using a monolayer of such a derivative yielded up to ten times higher doping levels, as measured by X-ray photoelectron spectroscopy and dynamic secondary mass spectroscopy, compared to an alkene with a single B atom. Sheet resistance measurements showed comparably increased conductivities of the Si substrates. Thermal budget analyses indicate that the doping level can be further optimized by changing the annealing conditions.
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Liang
authors.initials: L
authors.lastname: Ye
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Arántzazu
authors.initials: A
authors.lastname: González-Campo
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Núñez
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Michel P
authors.initials: MP
authors.lastname: de Jong
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Tibor
authors.initials: T
authors.lastname: Kudernac
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Wilfred G
authors.initials: WG
authors.lastname: van der Wiel
authors.affiliation: Molecular NanoFabrication group and ‡NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.|Functional Nanomaterials and Surfaces group and ∥Inorganic Materials and Catalysis group, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Jurriaan
authors.initials: J
authors.lastname: Huskens
keywords: carboranes; hydrosilylation; interfaces; monolayer doping; silicon doping