Off-axis electron holography is an electron microscopy-based technique that allows the electrostatic and magnetic fields in and around a specimen to be measured with nm-scale resolution. The continuous reduction in the size of semiconductor devices means that information about the distribution of strain fields and active dopants at a nanometre scale is required in order to understand how these ...

In this paper, we present a detailed simulation study of the influence of quantum mechanical effects in the inversion layer on random dopant induced threshold voltage fluctuations and lowering in sub-100 nm MOSFETs. The simulations have been performed using a three-dimensional (3-D) implementation of the density gradient (DG) formalism incorporated in our established 3-D atomistic simulation ap...

Doped catalyst-free GaAs nanowires have been grown by molecular beam epitaxy with the gallium-assisted method. The spatial dependence of the dopant concentration and resistivity have been measured by Raman spectroscopy and four point electrical measurements. Along with theoretical considerations, the doping mechanisms have been revealed. Two competing mechanisms have been revealed: dopant incor...

One of the major challenges towards scaling electronic devices to the nanometre-size regime is attaining controlled doping of semiconductor materials with atomic accuracy, as at such small scales, the various existing technologies suffer from a number of setbacks. Here, we present a novel strategy for controlled, nanoscale doping of semiconductor materials by taking advantage of the crystalline...

We present and review dopant mapping examples in semiconductor device structures by electron holography and outline their potential applications for experimental investigation of two-dimensional (2D) dopant diffusion on the nanometer scale. We address the technical challenges of the method when applied to transistor structures with respect to quantification of the results in terms of the 2D p-n...

The formation of a Schottky barrier at the metal-semiconductor interface is widely utilised in semiconductor devices. With the emerging of novel Schottky barrier based nanoelectronics, a further microscopic understanding of this interface is in high demand. Here we provide an atomistic insight into potential barrier formation and band bending by ab initio simulations and model analysis of a pro...

In recent years, a great deal of attention has been focused on the development of quantum wire transistors as a means of extending Moore’s Law. Here we present, results of fully three-dimensional, self-consistent quantum mechanical device simulations of InAs tri-gate nanowire transistor (NWT). The effects of inelastic scattering have been included as real-space self-energy terms. We find that t...

When a semiconductor host is doped by a foreign element, it is inevitable that a volume change will occur in the doped system. This volume change depends on both the size and charge state difference between the dopant and the host element. Unlike the "common expectation" that if the host is deformed to the same size as the dopant, then the formation energy of the dopant would reach a minimum, o...

Size-selected cationic transition-metal-doped silicon clusters have been studied with x-ray absorption spectroscopy at the transition-metal L2,3 edges to investigate the local electronic structure of the dopant atoms. For VSi16 + , the x-ray absorption spectrum is dominated by sharp transitions which directly reveal the formation of a highly symmetric silicon cage around the vanadium atom. In s...

Controlling axial and radial dopant profiles in nanowires is of utmost importance for NW-based devices, as the formation of tightly controlled electrical junctions is crucial for optimization of device performance. Recently, inhomogeneous dopant profiles have been observed in vapor–liquid–solid grown nanowires, but the underlying mechanisms that produce these inhomogeneities have not been compl...