We have employed an MeV He+ microbeam for the analysis of micron-scale semiconductor structures. The analysis combines a unique beam scanning and mapping capability with powerful ion beam techniques such as particleinduced x-ray emission, Rutherford backscattering and ion channeling. These analysis capabilities are applied to the measurement of dopant profiles in polycrystalline resistors, identification of micro-alloying in metal-GaAs contacts and damage/atom location in individual polycrystalline silicon grains. The latter application utilises the newly-developed technique of channeling contrast microscopy.

Small concentrations of phosphorus and boron in thin films have been measured by detection of proton induced prompt γ-rays. This technique is almost free of interference from other elements in the film or the substrate. Furthermore it is possible to obtain depth information without sputtering. The detection limit of both elements is around 100 ppm; depth resolution at shallow depths in silicon is about 50 nm in the case of boron, whereas it is better than 10 nm in the case of phosphorus.

As an application of this method, the incorporation of phosphorus and boron in thin films of hydrogenated amorphous silicon is measured. The films were prepared in a glow discharge reactor by mixing PH3 or B2H6 with the SiH4/H2 gas mixture.

We have developed an apparatus that provides a high flux, low energy, monoenergetic positron beam to investigate various processes which occur when a positron beam impinges on a metal surface, including annihilation at the surface, trapping in vacancies, and the emission of both fast and thermally desorbed positronium. We report here the first angular correlation of annihilation gamma-rays measurements and positronium time of flight experiments at a material surface. We applied a simple free electron model which explains the general trend of the data but differences due to the surface specific properties and the deviation from a free electron metal are evident.

The low temperature (300–400°C) out-diffusion of an underlying metal through a thin film overlayer of another metal has been studied in ambients of N2 and forming gas. Surface oxidation of this out-diffused metal can interfere with the attachment of terminating components used in semiconductor devices. AES depth profile analysis has shown that the out-diffusion of Ni through Au is suppressed in a forming gas ambient. It has also been shown that the extent of this out diffusion can be modified considerably by the presence of Cu.

Elastic recoil analysis using 44 MeV chlorine ions is a precise and timesaving method of measuring hydrogen profiles of ion implanted magnetic bubble garnets. Neon, nitrogen and hydrogen ion-implanted modified yttrium iron garnets, which are used for magnetic bubble devices based on ion implanted propagation patterns, (12P2), were studied with respect to their hydrogen concentration-depth distributions. A description and calibration of the elestic recoil analysis setup are presented along with the necessary simple algorithms to obtain the final hydrogen concentration-depth profiles from the measured energy spectra generated by recoiled protons. The garnet samples were annealed with or without a surface coating of SiO2. At 250°C, the hydrogen was found to diffuse throughout the aamaged surface layer but not into the underlying undamaged material. At 350°C, the hydrogen diffused out of the uncoated garnet, but was sealed into the implant damaged garnet layer by the thin oxide coating. Such hydrogen retention correlates with previously reported beneficial effects of an oxide layer deposited at a low temperature after implantation but before processing on ion implanted bubble devices.

Examples of the mass spectrometry of sputtered or evaporating neutral species obtained by SALI are presented for NBS Glass 610 (primarily a silicate), and an anodic oxide of HgCdTe. For the NBS glass, a SIMS spectra was recorded for comparison with SALI using the same apparatus. The raw SALI spectra of the glass is in semiquantitative accord with the known composition, in contrast to SIMS. Relative secondary ion yields can be determined for unknown complex materials by comparing SALI and SIMS spectra. Depth profiling measurements on the anodic oxides of Hg1−xCdxTe show a significant though depleted concentration of Hg in the oxide in contrast to numerous other analyses; this result is corroborated by RBS studies. Hg and also Te evaporation is monitored in real-time by SALI with large dynamic range capabilities.

This paper presents strong evidence for the influence of the density of oxide particles on the internal oxidation kinetics of silver based alloys. Measurements performed by Mbssbauer Spectroscopy, on 1 at% Sn in Ag alloys oxidized at temperatures between 523 and 823K, clearly indicate that the oxidation kinetics are described by a power law of the time with an exponent close to the unity for a high density of oxide particles (between 0.3 and 1.0×10−2 oxide particles per alloy atom). For low densities (<10−4 oxide particles per alloy atom), the exponent is close to 0.5). Previous kinetics measurements in AgIn alloys are shown to be in general agreement with this rule. These results can be interpreted on the basis of the existence of strain fields around the oxide particles, which produce a network of channels for easy oxygen migration when the density of oxide particles is high enough.

Rapid and unambiguous characterization of crystalline phases in submicron sputter deposited TiO2 films on silica substrates can be inferred from measured Raman spictra. Pure anatase and rutile, mixed phase, and amorphous films to thicknesses of several hundred Angstroms and greater yield Raman spectra exhibiting little interference from the substrate when the appropriate component of the scattered light is analyzed. In situ Raman spectra were acquired as a function of temperature to 900°C using conventional radiant heating techniques and to temperatures near 2000°C using 10.6μ radiation from a CW CO2 laser as a localized heating source. Pulsed Raman excitation/gated deiection techniques were used to minimize blackbody radiation interference at these high temperatures. Anatase and amorphous TiO2 films transform irreversibly to the rutile phase at temperatures below 900°C while rutile appears to be stable at much higher temperatures. Measurements performed on uncoated silica substrates at temperatures where the glass becomes fluid suggest that the strongly crosslinked glass has partially transformed into a chain-like structure.

This paper describes advances in the use of the energy loss background associated with individual photoelectron peaks. The subtraction of a Shirley-type background is now normal practice in quantitative XPS analysis. However, in the case of a composite peak containing features from differing depths the subtraction of a common background has a clear disadvantage: i.e. the proportion of background rise associated with each component should be different but is, in fact, fixed. A peak-fitting procedure is described which enables individual backgrounds to be used for each component. The method has been tested using evaporated overlayers and this enables a mean free path for electrons undergoing small energy losses (less than 10 eV) to be determined. The findings are in accord with those of Tougaard and Sigmund and suggest that the use of background intensities in conjunction with the peaks themselves enables the information depth of XPS to be extended by about 10%. A few observations on the behaviour and use in analysis of the large energy loss structure are made.

The use of the findings to aid in characterisation of the near surface distribution of elements and ions is described for the following systems: the distribution within oxide films on alloys; the locus of disbondment of organic films on metals; and the surface contamination of surfaces removed from aqueous media.