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The diffusion approximation of ion induced atomic mixing was employed to describe the expansion of Ge and B tracer profiles in Si during sputter depth profiling using O2+, Ar+, Kr+ and Cs+. The methodology is shown to generate superior quantitative agreement with experimental secondary ion mass spectrometry profiles. It also presents an accurate approach to deriving mixing efficiency.

Surface stylus profilometry is used for demonstrating the vertical expansion of a silicon surface subjected to 10 kilo electron volt oxygen ion bombardment. The bombardment expands the surface steadily, with an increase in the concentration of incorporated oxygen. Maximum expansion occurs when the bombardment dosage attains the critical value. Oxygen incorporation is observed by the profilometric method as a function of bombardment dosage. The swelling in the surface of silicon is attributed to the amount of oxygen dose during bombardment.

High resolution Rutherford backscattering and channeling help examine the generation of surface oxides during room temperature bombardment of silicon with oxygen in a secondary ion mass spectrometry system and suggest the formation of stoichiometric SiO2 at angles of incidence. The oxygen generation and strong Si-O bond formation indicate the ability of existing codes to explain angular and energy dependences. The reaching of a submerged SiO2 layer and saturation of Si bonds cause oxygen transport in SiO2 to extend the oxide towards the surface.

The depth profiles of mega-electron-volt boron ions implanted into amorphous silicon were investigated using secondary ion mass spectrometry. The results showed that the two samples featured a maximum relative shift of 3.5% in the range of 0.6 to 0.8 MeV. At higher energies, the maximum relative shift decreased gradually to approximately 1.006 at 5.0 MeV. This was attributed to a larger electronic stopping cross section.

The use of carbon ions as an implant species for controlling the surface conductivity of insulators was investigated. The results showed that ion beam induced surface conductivity to increase by as much as eight orders of magnitude. In contrast, Xe implantation did not result in any changes. This indicated that the increase in surface conductivity was due to the presence of carbon in the fused quartz matrix and not due to damage.

The use of a sacrificial carbon surface layer deposited on the target surfaceto protect it from sputtering during a high dose heavy ion implantation processwas investigated. The results showed that the carbon layer effectively shieldedthe target from sputtering damage. However, as the implantation energy was increased, a significant degree of carbon mixing was observed at the C/Cu interface.

We have studied the electronic structure of nitinol exposed to low-energy oxygen-ion bombardment, using x-ray photoemission spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy. XPS spectra reveal a gradual transformation of nitinol surfaces into TiO2 with increased dose of implanted oxygen. No oxidation of Ni atoms has been detected. NEXAFS spectra around O K-edge and Ti L2,3-edge, reflecting the element-specific partial density of empty electronic states, exhibit features, which can be attributed to the creation of molecular orbitals, crystal field splitting, and the absence of long-range order, characteristic of the amorphous TiO2. Based on these results, we discuss the oxidation kinetics of nitinol under low-energy oxygen-ion bombardment. [ABSTRACT FROM AUTHOR]

Formation of defects in hexagonal and cubic boron nitride (h-BN and c-BN, respectively) under low-energy argon or nitrogen ion-bombardment has been studied by near-edge x-ray absorption fine structure (NEXAFS) around boron and nitrogen K-edges. Breaking of B–N bonds for both argon and nitrogen bombardment and formation of nitrogen vacancies, VN, has been identified from the B K-edge of both h-BN and c-BN, followed by the formation of molecular nitrogen, N2, at interstitial positions. The presence of N2 produces an additional peak in photoemission spectra around N 1s core level and a sharp resonance in the low-resolution NEXAFS spectra around N K-edge, showing the characteristic vibrational fine structure in high-resolution measurements. In addition, several new peaks within the energy gap of BN, identified by NEXAFS around B and N K-edges, have been assigned to boron or nitrogen interstitials, in good agreement with theoretical predictions. Ion bombardment destroys the cubic phase of c-BN and produces a phase similar to a damaged hexagonal phase. [ABSTRACT FROM AUTHOR]

We have studied the interaction of low-energy nitrogen ions (0.3–2 keV N2+) with GaAs (100) surfaces by photoemission spectroscopy (PES) around N 1s and Ga 3d core levels and near-edge x-ray absorption fine structure (NEXAFS) around the N K edge. At the lowest bombardment energy, nitrogen forms bonds with both Ga and As, while Ga-N bonds form preferentially at higher energies. Thermal annealing at temperatures above 350 °C promotes the formation of GaN on the surface, but it is insufficient to remove the disorder introduced by ion implantation. Nitrogen interstitials and antisites have been identified in NEXAFS spectra, while interstitial molecular nitrogen provides a clear signature in both PES and NEXAFS. [ABSTRACT FROM AUTHOR]

Impurity-free disordering (IFD) of uniformly doped p-GaAs epitaxial layers was achieved using either undoped or doped (Ga or P) spin-on-glass (SOG) in conjunction with rapid thermal annealing in the temperature range from 800 to 925 °C. Capacitance-voltage measurements showed a pronounced increase in the doping concentration (NA) in the near-surface region of the layers disordered using both undoped and P:SOG. The increase in NA showed an Arrhenius-like dependence on the inverse of annealing temperature. On the other hand, NA did not change significantly for Ga-doped SOG. These changes can be explained by the relative injection of excess gallium vacancies (VGa) during IFD of p-GaAs by the different SOG layers. Deep-level transient spectroscopy showed a corresponding increase in the concentration of a defect HA (EV+0.39 eV), which can be attributed to Cu, in the undoped and P:SOG disordered p-GaAs layers, but not in the epilayers disordered by Ga:SOG. We have explained the increase in free carrier concentration by the segregation of Zn atoms towards the surface during the injection of VGa. The redistribution of Zn during disordering of buried marker layers in GaAs and Al0.6Ga0.4As using either undoped or Ga-doped SOG was verified by secondary-ion mass spectrometry. [ABSTRACT FROM AUTHOR]

Synchrotron-based near edge X-ray absorption fine structure (NEXAFS) spectroscopy was used to study the electronic of nitrogen-related defects in InN(0001). The NEXAFS revealed several defects created by ion-bombardment within the band gap or the conduction band around the nitrogen K-edge of InN and it also provided conclusive experimental evidence for the formation of interstitial nitrogen.

Presents a study which examined carbon delta-doped Al[subx]Ga[sub1-x]As grown in metalorganic vapor phase epitaxy. Review of related literature; Description of the experimental setup; Results.

Presents a study that observed a very significant zinc evaporation from nongrowing aluminum-gallium-arsenic surface during a post-δ-doping purge step in growth of zinc δ-doped aluminum-gallium-arsenic by low pressure metal organic vapor phase epitaxy. Use of dimethylzinc as a doping precursor; Proposal for a δ-doping sequence different from the normal purge-doping-purge; Dopant memory effect.