title: Structural Mapping of Functional Ge Layers Grown on Graded SiGe Buffers for sub-10 nm CMOS Applications Using Advanced X-ray Nanodiffraction.
abstract: We report a detailed advanced materials characterization study on 40 nm thick strained germanium (Ge) layers integrated on 300 mm Si(001) wafers via strain-relaxed silicon-germanium (SiGe) buffer layers. Fast-scanning X-ray microscopy is used to directly image structural inhomogeneities, lattice tilt, thickness, and strain of a functional Ge layer down to the sub-micrometer scale with a real space step size of 750 μm. The structural study shows that the metastable Ge layer, pseudomorphically grown on Si(0.3)Ge(0.7), exhibits an average compressive biaxial strain of -1.27%. By applying a scan area of 100 × 100 μm(2), we observe microfluctuations of strain, lattice tilt, and thickness of ca. ±0.03%, ±0.05°, and ±0.8 nm, respectively. This study confirms the high materials homogeneity of the compressively strained Ge layer realized by the step-graded SiGe buffer approach on 300 mm Si wafers. This presents thus a promising materials science approach for advanced sub-10 nm complementary metal oxide-semiconductor applications based on strain-engineered Ge transistors to outperform current Si channel technologies.
authors.affiliation: ID01/ESRF, The European Synchrotron , 71 rue des Martyrs, 38043 Grenoble Cedex, France.|Aix-Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334 , 13397 Marseille Cedex 20, France.
authors.forename: Marie-Ingrid
authors.initials: MI
authors.lastname: Richard
authors.affiliation: IHP , Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.
authors.forename: Marvin H
authors.initials: MH
authors.lastname: Zoellner
authors.affiliation: ID01/ESRF, The European Synchrotron , 71 rue des Martyrs, 38043 Grenoble Cedex, France.
authors.forename: Gilbert A
authors.initials: GA
authors.lastname: Chahine
authors.affiliation: IHP , Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Zaumseil
authors.affiliation: IHP , Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Capellini
authors.affiliation: Siltronic AG , Hans-Seidel-Platz 4, 81737 München, Germany.
authors.forename: Maik
authors.initials: M
authors.lastname: Häberlen
authors.affiliation: Siltronic AG , Hans-Seidel-Platz 4, 81737 München, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Storck
authors.affiliation: ID01/ESRF, The European Synchrotron , 71 rue des Martyrs, 38043 Grenoble Cedex, France.
authors.forename: Tobias U
authors.initials: TU
authors.lastname: Schülli
authors.affiliation: IHP , Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.|Institute of Physics and Chemistry, Brandenburg University of Technology , 03046 Cottbus, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schroeder
keywords: CMOS; Ge layer; nanodiffraction; strain; structural mapping