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Notes: Abstract Several analytical techniques have been used to characterize homogeneous films of tungsten-containing hydrogenated carbon (W-C: H), deposited on Si with a film thickness of 1–1.5 μm. Electron probe microanalysis (EPMA) enables one to determine the major components W (3–43 at %) and C, impurities (〈 2 at %) of Ar and O, and the mass thickness (300–1800 μg/cm2) of the films. The agreement between the results of EPMA and the data (W-content, mass thickness) provided by Rutherford backscattering spectrometry (RBS) is 5–10% relative. Quantitative analysis of hydrogen in W-C:H films (1–16 at %) is carried out by the technique of elastic recoil detection (ERD). A suitable scheme for the determination of H in W-C: H films by SIMS is proposed, based on monitoring the intensity ratio of HCs+/CCs+ secondary ions.

Notes: Summary Immunohistochemical staining of epidermal growth factor receptor (EGF-R) with a monoclonal antibody was performed in 43 biopsies of cervical tissue. The distribution of the receptors in normal cervical tissue differs from that of cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma of the cervix. Whereas the staining reaction in normal squamous epithelium was confined to the basal and deep parabasal cell layer, in all cervical intraepithelial neoplasias, with or without human papilloma virus association, a homogeneous EGF-R staining reaction could be observed throughout the entire lesion. This means that the dysplasia cells of a CIN I-III, like the tumor cells of a squamous cell carcinoma, have a raised EGF-R content, which in the normal squamous epithelium is usually only found in the basal and deep parabasal cells that are capable of dividing. No EGF-R staining reaction could be detected in the higher, differentiated cell layers of the normal squamous epithelium of the cervix.

Notes: Secondary ion yields are known to be strongly enhanced by the presence of oxygen in the analysed sample. The magnitude of the yield enhancement is often significantly different for impurity and matrix ion species. This kind of SIMS matrix effect severely aggravates concentration calibration in depth profiling through regions of transiently varying oxygen concentration. To eliminate the matrix effect, a procedure has been developed that allows the differences in yield enhancement to be corrected in a quantitative manner. The procedure will ultimately be required to calibrate profiles extending through native surface oxide layers. The calibration exercise was carried out for boron in silicon. The dependence of the B+/Si+ sensitivity ratio, RB,Si, on the oxygen content of the sample was explored in situ by implanting 1.9 keV O2+ ions at O° (normal incidence) into a uniformly B-doped reference sample, followed by sputter profiling through the synthesized oxide with the same beam incident at 75°. All measurements were performed at base pressure. During oxygen build-up after initial sputter cleaning the Si+ and SiO+ yields increased by factors of 200 and 500, respectively, whereas for B+ the yield increased only 40 times. Almost inverse yield changes were observed during oxide removal. Bombardment-induced mixing caused a broadening of the oxide/Si interface and some relocation of B atoms. Under internally consistent assumptions the relatively small boron mixing effect could be separated from the oxygen-induced B+ yield enhancement effect. The normalized SiO+ signal ĨSiO+, was used as a measure of the oxygen content of the samples bombarded at the two different impact angles. The B+ yields and the sensitivity ratios RB,Si(ĨSiO+) could be fitted very well by polynomial functions. The polynomials were employed to quantify the depth profiles of 0.5 and 2 keV 11B implanted in Si test samples covered with 6 nm layers of thermal SiO2 (i.e. thinner than the synthesized oxide layer that can be produced by the 1.9 keV O2+ beam at O°). The compositional changes encountered in passing from the thermal oxide into the Si substrate had be taken into account, not only for time-to-depth conversion but also for concentration calibration based on the measured sensitivity ratios. The changes in erosion rate and Si density around the interface were modelled by error functions. Direct evidence is presented that, for accurate calibration, density and sensitivity changes must be treated separately. Even though the through-oxide variations of RB,Si are quite different for O° and 75°, the calibrated 2 keV 11B profiles derived from measurements at these two vastly different impact angles agree very well, even at the interface. This implies that the large matrix effect occurring in through-oxide profiling at 75° can be eliminated using the new calibration procedure. Minor differences (〈10%) between the calibrated 2 keV 11B profiles from measurements at 0° and 75° can be attributed to differences in bombardment-induced relocation. The mixing effect is particularly severe for the profiles of the very narrow and shallow 0.5 keV 11B implantation distributions, which turned out to be heavily distorted at depths below 10 nm, both at 0° and 75°. Hence it is mandatory, for reasonably accurate profile measurements, to use O2+ energies that are significantly (∽50%) lower than the implantation energy, both for normal and oblique incidence of the probing beam. © 1998 John Wiley & Sons, Ltd.