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Abstract: By using a self-assembled monolayer of octadecylphosphonic acid molecules, C[H.sub.3][(C[H.sub.2]).sub.17] PO[(OH).sub.2], on mica as a model of the 'soft' materials, such as self-assembled monolayers (SAMs) and multilayers in many [...]

Abstract: In the context of collision-induced dissociation in chemistry and kinematics in physics, we have determined that a beam of hyperthermal protons can be used as tiny hammers to preferentially [...]

Time-of-flight scattering and recoiling spectrometry was used in studying low-keV ion channeling in hydrogen. Ion channeling is the manipulation of a beam of energetic ions into open spaces between close-packed rows or planes of atoms in a crystal. Results indicate that H atoms preferentially populated the threefold fcc sites at a height of 0.9 plus/minus 0.1 angstrom above the first-layer Pt atoms. The corresponding lenght of the Pt-H bond had the same value.

Ion bombardment is used to illustrate the surface damage of InP caused by brief plasma exposure. Findings show that argon bombardment with an impact of 10 eV could induce surface defects. The bombardment is equal to the brief plasma exposure a semiconductor can experience in a common electron cyclotron resonance plasma enhanced chemical vapor deposition of a passivating dielectric on InP. Thus, the semiconductor surface must be protected against plasma surface damage.

The mechanism of sulphur diffusion at the interface between a silicon heterolayer and a sulphur-protected gallium arsenide(100) layer was investigated. Specifically, particle induced x-ray emission and Rutherford backscattering spectrometry were employed to observe the depth distribution of sulphur. In addition, x-ray absorption near-edge structure and x-ray photoemission spectroscopy were used to examine the interfacial structure.

X-ray absorption near-edge structure spectroscopy and low energy electron diffraction studies reveal the properties of the surface defect structures on diamond (100) surfaces. Low energy bombardment with neon ions causes surface defect structures. If bombardment occurs at very low ion fluence, diamond discrete exciton absorption is suppressed. The process of thermal annealing up to 1,100 degrees Celsius has no effect on the bombardment stimulated defect structure.

Low-energy carbon ion beam is used to develop diamond-like films having dual amorphous carbon phase structure. The energy difference between two phases is due to defects produced through ion bombardment. Film/substrate interface has no defective phase and the film is not uniform in depth. Film adhesion is enhanced through a carbide phase, which is observed at the interface between the film and the substrate.

Polysulfide treatment decreased the density of interface defect states proximal to the conduction-band edge in InP metal/insulator/semiconductor diodes that were. Capacitance-voltage measurements and deep-level transient spectroscopy facilitated the study of deep-level bulk and interface defect states in these semiconductor diodes.

Vacancies and self interstitials in the near surface region of diamond were formed during argon and carbon ion bombardment of diamond even at bombardment energies less than 1 kilo electron volts. Vacancies and vacancy clusters formed internal surfaces that resembled atomically reconstructed clean diamond surface, while the aggregation of former defects formed edge dislocations.

Mass-separated, low energy ion beam system and X-ray photoelectron spectroscopy facilitated the 35Cl+ bombardment of Si(100) surfaces, resulting in the desorption of the surface silicon chlorides. Chlorine chemistry enhancement is observed during the etching of the silicon surface with the chlorine ions.

Argon incorporation probabilities in silicon reduces with decreasing energy in the bombardment energy range 15 to 1000 electron volts, while the incorporation probability is less than unity when the bombardment energy ranges between 15 and 100 electron volts. X-ray photoelectron spectroscopy that was polar angle-dependent and Rutherford backscattering spectroscopy facilitated the low energy ion bombardment study of argon incorporation in Si(100).

The effect of indium phosphide low energy ion bombardment on alkane-based reactive ion etching was investigated using polar-angle dependent x-ray photolectron spectroscopy and hermal annealing. . The results showed that carbon ion bombardment resulted in carbon inccorporation and a significant change in the semiconductor surface composition. Addiional carbon ion bombardment caused deposiion of amorphous carbon residue.

Although an increasing volume of x-ray photoemission spectroscopic (XPS) data has been accumulated on boron and boron-rich compounds because of their unusual properties, including a unique three-center, two-electron bonding configuration, their common nonmetallic nature has been overlooked. Typically, the measured energy-state data are not clarified by surface Fermi level positions of these nonmetallic samples, which compromises the scientific contents of the data. In the present study, we revisited the XPS studies of sputter-cleaned β-rhombohedral boron (β[sub r]-B), the oxidized surface of β[sub r]-B, B[sub 6]O pellet, and polished B[sub 2]O[sub 3], to illustrate the impact and resolution of this scientific issue. These samples were chosen because β[sub r]-B is the most thermodynamically stable polytype of pure boron, B[sub 2]O[sub 3] is its fully oxidized form, and B[sub 6]O is the best known superhard family member of boron-rich compounds. From our XPS measurements, including those from a sputter-cleaned gold as a metal reference, we deduced that our β[sub r]-B had a surface Fermi level located at 0.7±0.1 eV from its valence-band maximum (VBM) (referred as E[sub FL]) and a binding energy for its B 1s core level at 187.2 eV from VBM (E[sub b,VBM]). The latter attribute, unlike typical XPS binding energy data that are referenced to a sample-dependent Fermi level (E[sub b,FL]), is immune from any uncertainties and variations arising from sample doping and surface charging. For bulk B[sub 2]O[sub 3], we found an E[sub b,VBM] for its B 1s core level at 190.5 eV and an E[sub b,FL] at 193.6 eV. For our β[sub r]-B subjected to a surface oxidation treatment, an overlayer structure of ∼1.2 nm B[sub 2]O[sub 3]/∼2 nm B[sub 2]O/B was found. By comparing the data from this sample and those from β[sub r]-B and bulk B[sub 2]O[sub 3], we infer that the oxide overlayer carried some negative fixed charge and this induced on the semiconducting β[sub r]-B sample an upward surface band bending of ∼0.6 eV. As for our B[sub 6]O sample, we found an E[sub FL] of ∼1.7 eV and two different chemical states having E[sub b,VBM] of 185.4 and 187.2 eV, with the former belonging to boron with no oxygen neighbor and the latter to boron with an oxygen neighbor. The methodology in this work is universally applicable to all nonmetallic samples. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

X-ray photoemission spectroscopy and capacitance-voltage measurements help analyze the properties and the chemical structure of the interfaces of metal-insulator-semiconductor capacitors on cleaved n-GaAs (110) facets. Passivation processes do not enhance the C-V characteristics while silicon interface control layer method enhances the C-V properties. The capacitors have a minimum interface state density value of 10 to the power of 12 e/V per sq cm.

The optimization and calibration of the optical lever detection sensitivity for an atomic force microscopy (AFM) cantilever-tip ensemble vibrating in high-order flexural modes and experiencing a wide range and variety of tip-sample interactions are analyzed. A calibration method is proposed to determine the actual AFM detection sensitivity in high-order flexural vibration modes against the static end-load sensitivity that is obtained by measuring a force-distance curve on a hard substrate in the contact mode.

The rapid advances in quantitative biology and polymer science have led to the atomic force microscope (AFM) being used for single-molecule force spectroscopy. The correction factor charts are present for easy calculation of correction factors for a wide variety of stiffness of single molecules.