The stopping and range of ions in matter is physically very complex, and there are few simple approximations which are accurate. However, if modern calculations are performed, the ion distributions can be calculated with good accuracy, typically better than 10%. This review will be in several sections: 

a)

A brief exposition of what can be determined by modern calculations.




b)

A review of existing widely-cited tables of ion stopping and ranges.




c)

A review of the calculation of accurate ion stopping powers.

The stopping and range of ions in solids

Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...

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Dye-Sensitized Solar Cells

Two-dimensional crystals are emerging materials for nanoelectronics. Development of the field requires candidate systems with both a high carrier mobility and, in contrast to graphene, a sufficiently large electronic bandgap. Here we present a detailed theoretical investigation of the atomic and electronic structure of few-layer black phosphorus (BP) to predict its electrical and optical properties. This system has a direct bandgap, tunable from 1.51 eV for a monolayer to 0.59 eV for a five-layer sample. We predict that the mobilities are hole-dominated, rather high and highly anisotropic. The monolayer is exceptional in having an extremely high hole mobility (of order 10,000 cm(2) V(-1) s(-1)) and anomalous elastic properties which reverse the anisotropy. Light absorption spectra indicate linear dichroism between perpendicular in-plane directions, which allows optical determination of the crystalline orientation and optical activation of the anisotropic transport properties. These results make few-layer BP a promising candidate for future electronics.

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High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus

The purpose of this chapter is to review the calculation f the stopping and the final range distribution of ions in matter. During the last thirty years there have been published scores of tables and books evaluating the parameters of energetic ion penetration of matter. Rarely have the authors of these reference works included any evaluation of the accuracy of the tabulated numbers. We have chosen to show the development of ion penetration theory by tracing how, as the theory developed through the years, various parts have been incorporated into tables and increased their accuracy. This approach restricts our comments to those theoretical advances which have made significant contributions to the obtaining of practical ion stopping powers and range distributions. The Tables reviewed were chosen because of their extensive citation in the literature.

The Stopping and Ranges of Ions in Matter

Atomic layer deposition(ALD), a chemical vapor deposition technique based on sequential self-terminating gas–solid reactions, has for about four decades been applied for manufacturing conformal inorganic material layers with thickness down to the nanometer range. Despite the numerous successful applications of material growth by ALD, many physicochemical processes that control ALD growth are not yet sufficiently understood. To increase understanding of ALD processes, overviews are needed not only of the existing ALD processes and their applications, but also of the knowledge of the surface chemistry of specific ALD processes. This work aims to start the overviews on specific ALD processes by reviewing the experimental information available on the surface chemistry of the trimethylaluminum/water process. This process is generally known as a rather ideal ALD process, and plenty of information is available on its surface chemistry. This in-depth summary of the surface chemistry of one representative ALD process aims also to provide a view on the current status of understanding the surface chemistry of ALD, in general. The review starts by describing the basic characteristics of ALD, discussing the history of ALD—including the question who made the first ALD experiments—and giving an overview of the two-reactant ALD processes investigated to date. Second, the basic concepts related to the surface chemistry of ALD are described from a generic viewpoint applicable to all ALD processes based on compound reactants. This description includes physicochemical requirements for self-terminating reactions,reaction kinetics, typical chemisorption mechanisms, factors causing saturation, reasons for growth of less than a monolayer per cycle, effect of the temperature and number of cycles on the growth per cycle (GPC), and the growth mode. A comparison is made of three models available for estimating the sterically allowed value of GPC in ALD. Third, the experimental information on the surface chemistry in the trimethylaluminum/water ALD process are reviewed using the concepts developed in the second part of this review. The results are reviewed critically, with an aim to combine the information obtained in different types of investigations, such as growth experiments on flat substrates and reaction chemistry investigation on high-surface-area materials. Although the surface chemistry of the trimethylaluminum/water ALD process is rather well understood, systematic investigations of the reaction kinetics and the growth mode on different substrates are still missing. The last part of the review is devoted to discussing issues which may hamper surface chemistry investigations of ALD, such as problematic historical assumptions, nonstandard terminology, and the effect of experimental conditions on the surface chemistry of ALD. I hope that this review can help the newcomer get acquainted with the exciting and challenging field of surface chemistry of ALD and can serve as a useful guide for the specialist towards the fifth decade of ALD research.

Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process

Single-walled carbon nanotubes (SWNT) are grown by a plasma enhanced chemical vapor deposition (PECVD) method at 600 °C. The nanotubes are of high quality as characterized by microscopy, Raman spectroscopy, and electrical transport measurements. High performance field effect transistors are obtained with the PECVD nanotubes. Interestingly, electrical characterization reveals that nearly 90% of the nanotubes are semiconductors and thus highly preferential growth of semiconducting over metallic tubes in the PECVD process. Control experiments with other nanotube materials find that HiPco nanotubes consist of ∼61% semiconductors, while laser ablation preferentially grows metallic SWNTs (∼70%). The characterization method used here should also be applicable to assessing the degree of chemical separation of metallic and semiconducting nanotubes.

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Preferential Growth of Semiconducting Single-Walled Carbon Nanotubes by a Plasma Enhanced CVD Method

The phonon‐limited mobility of strained Si metal–oxide–semiconductor field‐effect transistors (MOSFETs) fabricated on a SiGe substrate is investigated through theoretical calculations including two‐dimensional quantization, and compared with the mobility of conventional (unstrained) Si MOSFETs. In order to match both the mobility of unstrained Si MOSFETs and the mobility enhancement in strained Si MOSFETs, it is necessary to increase the coupling of electrons in the two‐dimensional gas with intervalley phonons, compared to the values used in conventional models. The mobility enhancement associated with strain in Si is attributed to the following two factors: the suppression of intervalley phonon scattering due to the strain‐induced band splitting, and the decrease in the occupancy of the fourfold valleys which exhibit a lower mobility due to the stronger interaction with intervalley phonons. While the decrease in the averaged conductivity mass, caused by the decrease in the occupancy of the fourfold valle...

Comparative study of phonon‐limited mobility of two‐dimensional electrons in strained and unstrained Si metal–oxide–semiconductor field‐effect transistors

Deep submicron strained-Si n-MOSFETs were fabricated on strained Si/relaxed Si/sub 0.8/Ge/sub 0.2/ heterostructures. Epitaxial layer structures were designed to yield well-matched channel doping profiles after processing, allowing comparison of strained and unstrained Si surface channel devices. In spite of the high substrate doping and high vertical fields, the MOSFET mobility of the strained-Si devices is enhanced by 75% compared to that of the unstrained-Si control devices and the state-of-the-art universal MOSFET mobility. Although the strained and unstrained-Si MOSFETs exhibit very similar short-channel effects, the intrinsic transconductance of the strained Si devices is enhanced by roughly 60% for the entire channel length range investigated (1 to 0.1 /spl mu/m) when self-heating is reduced by an ac measurement technique. Comparison of the measured transconductance to hydrodynamic device simulations indicates that in addition to the increased low-field mobility, improved high-field transport in strained Si is necessary to explain the observed performance improvement. Reduced carrier-phonon scattering for electrons with average energies less than a few hundred meV accounts for the enhanced high-field electron transport in strained Si. Since strained Si provides device performance enhancements through changes in material properties rather than changes in device geometry and doping, strained Si is a promising candidate for improving the performance of Si CMOS technology without compromising the control of short channel effects.

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Fabrication and analysis of deep submicron strained-Si n-MOSFET's

Projected Range Statistics: Semiconductors and Related Materials

Rapid thermal processing was used to diffuse Si into GaAs from a thin elemental source. Several encapsulants were applied. The diffusion was found to be dependent on the type of encapsulant. A model is developed based on the formation and rapid diffusion of Si nearest neighbor donor‐acceptor pairs. Results from the codiffusion of Si and Ge support this model.

James F. Gibbons

Papers

Preferential Growth of Semiconducting Single-Walled Carbon Nanotubes by a Plasma Enhanced CVD Method

Comparative study of phonon‐limited mobility of two‐dimensional electrons in strained and unstrained Si metal–oxide–semiconductor field‐effect transistors

Fabrication and analysis of deep submicron strained-Si n-MOSFET's

Projected Range Statistics: Semiconductors and Related Materials

Diffusion of silicon in gallium arsenide using rapid thermal processing: Experiment and model