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The stoichiometry and thickness of TiNxOy films has been determined by electron microprobe and nuclear microanalysis. The difficulty arising in the electron microprobe from the interference between NKα and TiLI lines has been overcome by using a suitable Monte Carlo computing scheme. This procedure takes into account the SiKα intensity which was found to be sensitive to composition and thickness of the overlying TiNxOy film. The good agreement between electron microprobe and nuclear microanalysis results indicate the validity of the method.

Phosphorus predepositions are performed at 920 and 1000 °C on (100) silicon wafers, previously implanted with chlorine doses ranging from 5 × 1013 to 1 × 1016 cm−2. From the comparison with unimplanted specimens, it is observed that chlorine reduces the concentration of silicon interstitials produced by the doping process. This reduction results in a shallowing of the high diffusivity tail of the carrier profile and in preventing the formation of interstitial-type dislocations. Bei 920 und 1000 °C werden an (100)-Siliziumwafer, die zuvor mit Chlor im Dosisbereich von 5 × 1013 bis 1 × 1016 cm−2 implantiert wurden, Phosphorvorbelegungen durchgefuhrt. Aus dem Vergleich mit nichtimplantierten Proben wird beobachtet, das Chlor die Konzentration von Si-Zwischengitterstorstellen verringert, die durch den Dotierungsprozes erzeugt werden. Diese Verringerung fuhrt zu einer Erniedrigung des hohen Diffusionsauslaufers im Ladungstragerprofil und zur Vermeidung von Zwischengitterversetzungsbildung.

A Monte Carlo code previously used in modelling x-ray emission by incident electrons of several tens of kilo-electronvolts has been extended up to 300 keV, which is typical of the present medium-energy transmission electron microscopes. With the aid of a further numerical code, both the thickness and composition of thin self-supporting films can be simultaneously determined. This code exploits the bootstrap statistical method, which provides a realistic error analysis of the final results from the precision of the experimental data. The potential of the two codes is illustrated through a simulated example of a single self-supporting film. Such calculations can also be applied to two or more overlying films transparent to an electron beam.

SUMMARY The ability of an end-window variable geometry flow proportional counter to detect the ultrasoft BeK and SiL X-ray lines induced by the electron beam of a transmission electron microscope (TEM) has been demonstrated. This counter has been used in the current work in the energy dispersive mode, and has been equipped with a Formvar window about 400 nm thick, aluminized on both sides with a layer of 65 nm total thickness. X-ray peaks generated by specimens of other light elements such as boron, carbon, oxygen, fluorine and aluminium, and detected with this technique, are also reported. In the case of the BK line, the counting rate obtained with this detector has been evaluated and compared with that of a crystal spectrometer equipped with a conventional side-window flow proportional counter. Finally, a linear relationship between X-ray energy and detected pulse height was found for the lines examined, i.e. from the SiL up to the SiK X-rays.

The contrast in HREM images of small spherical coherent precipitates in silicon, having a hypothetical sphalerite structure and an SiX composition, is computed by the multislice method; X represents a dopant (or impurity) atom, ranging from boron up to platinum. The particles are assumed to have a diameter of 2 nm and to exert different amounts of in situ strain ϵ on the silicon matrix. The ideal case of no misfit (ϵ = 0) is also considered. For in situ strains 0 < ϵ < 2%, the maximum contrast, corresponding to the optimum defocus, depends mainly on the atomic number of the element X. For larger strains, which can occur in some cases if the SiX bond length in the SiX particle is determined by the covalent radius of the impurity atom X, the strain contrast dominates over the structure factor contrast. Der Kontrast in hochauflosenden, elektronenmikroskopischen Abbildungen kleiner, kugelformiger, koharenter Ausscheidungen in Silizium, die eine hypothetische Sphaleritstruktur und die Zusammensetzung SiX haben, wird mittels der Vielschichtmethode berechnet; X stellt hier ein Dotierungs- bzw. Verunreinigungsatom von Bor bis Platin dar. Es wird angenommen, das die Ausscheidungen einen Durchmesser von 2 nm haben und verschiedene in-situ-Dehnungen ϵ auf die Siliziummatrix ausuben. Der Idealfall, wo keine Fehlanpassung (ϵ = 0) vorhanden ist, wird auch betrachtet. Fur 0 < ϵ < 2% ist der maximale Kontrast, der der optimalen Defokussierung entspricht, hauptsachlich von der Atomzahl des X-Elementes abhangig. Fur grosere Dehnungen, die in einigen Fallen vorkommen konnen, wenn die SiX-Bindungslange im SiX-Teilchen vom kovalenten Radius des X-Verunreinigungsatoms bestimmt wird, uberwiegt der Dehnungskontrast den Strukturfaktorkontrast.