β-Disubstituted Pentacene Derivatives: Thin Film Structural Properties and Four-Probe Field Effect Mobility.

2,9- and 2,10-diphenylpentacene were synthesized by direct C-H borylation of ketal-protected pentacene, followed by halodeboronation, resolution of the dihalo isomers, Suzuki arylation, cleavage of the ketals and decarbonylation in the solid state. They were studied as main active components in organic field effect transistors (OFETs). Diphenyl substitution of pentacene affects the unit cell dimensions only slightly, preserving a face to edge molecular packing in the first layers of thin films evaporated on SiO substrates.

Large-Scale Monolithic Fabrication of III-V Vertical Nanowires on a Standard Si(100) Microelectronic Substrate.

Vertical III-V nanowires are of great interest for a large number of applications, but their integration still suffers from manufacturing difficulties of these one-dimensional nanostructures on the standard Si(100) microelectronic platform at a large scale. Here, a top-down approach based on the structure of a thin III-V epitaxial layer on Si was proposed to obtain monolithic GaAs or GaSb nanowires as well as GaAs-Si nanowires with an axial heterostructure. Based on a few complementary metal-oxide-semiconductor-compatible fabrication steps, III-V nanowires with a high crystalline quality as well as a uniform diameter (30 nm), morphology, positioning, and orientation were fabricated.

An Improved STEM/EDX Quantitative Method for Dopant Profiling at the Nanoscale.

In this paper, an improved quantification technique for STEM/EDX measurements of 1D dopant profiles based on the Cliff-Lorimer equation is presented. The technique uses an iterative absorption correction procedure based on density models correlating the local mass density and composition of the specimen. Moreover, a calibration and error estimation procedure based on linear regression and error propagation is proposed in order to estimate the total measurement error in the dopant density.

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si Ge and Si layers.

In this paper, we present an enhanced differential Hall effect measurement method (DHE) for ultrathin Si and SiGe layers for the investigation of dopant activation in the surface region with sub-nanometre resolution. In the case of SiGe, which constitutes the most challenging process, we show the reliability of the SC1 chemical solution (NHOH/HO/HO) with its slow etch rate, stoichiometry conservation and low roughness generation. The reliability of a complete DHE procedure, with an etching step as small as 0.