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[en] The reaction of ground-state silicon ion with water is investigated by using guided ion beam mass spectrometry. Absolute reaction cross sections are determined as a function of the relative collision energy. Thermochemistry of silicon species are derived from the thresholds of the reactions. (Author)
[en] Several solid state quantum computer schemes are based on the manipulation of electron and nuclear spins of single donor atoms in a solid matrix. The fabrication of qubit arrays requires the placement of individual atoms with nanometer precision and high efficiency. In this paper we describe first results from low dose, low energy implantations and our development of a low energy (<10 keV), single ion implantation scheme for 31Pq+ ions. When 31Pq+ ions impinge on a wafer surface, their potential energy (9.3 keV for P15+) is released, and about 20 secondary electrons are emitted. The emission of multiple secondary electrons allows detection of each ion impact with 100% efficiency. The beam spot on target is controlled by beam focusing and collimation. Finally, exactly one ion is implanted into a selected area avoiding a Poissonian distribution of implanted ions.
[en] The literature data on Si XI (Be-like ion) have been compiled with a critical re-analysis for their consistency. High-resolution EUV beam-foil spectra provided new data. With the help of Cowan code ab initio and parametric calculations and of isoelectronic comparisons a revised level scheme was constructed which includes most levels up to configurations with principal quantum number n = 5, as well as some n = 6 levels. About 200 spectral lines in the region 30-613 A are newly identified with transitions between configurations with n = 2, 3, 4, 5 and 6. (orig.)
[en] Highlights: • A glass–ceramic joining material for SiC was studied. • Bulk glass-ceramic material and joints were irradiated by Si-ion at 400 °C and 800 °C. • Irradiation-induced morphological and structural changes were investigated. • No cracking and damage were observed after irradiation. • The glass-ceramic is a promising joining material for nuclear reactor components.
[en] Si+ ion implantation into Si under inclined incidence angle was applied to demonstrate that Cu gettering in the region around half of the projected ion range, RP/2, of ion-implanted Si is controlled by the same mechanism working for excess vacancy generation. The obtained results directly relate the appearance of the RP/2 gettering effect to the radiation-induced excess vacancies. Excess vacancies were found to be the source of the dominating gettering sites of Cu at RP/2. Moreover, it is shown that the undesired impurity trapping at RP/2 can be prevented by means of additional Si+ implantation into the vacancy-rich region of ion-implanted Si to balance the excess of vacancies. The parameters in order to remove Cu gettering at RP/2 are determined for the additional Si+ implantation. If the threshold fluence necessary to remove the Cu gettering at RP/2 is exceeded, the excess vacancies are overcompensated and new interstitial-type dislocation loops form
[en] The charge-transfer rate coefficient for the reaction Si3+(3s2S)+He→products is measured by means of a combined technique of laser ablation and ion storage. A cylindrical radio-frequency ion trap was used to store Si3+ ions produced by laser ablation of solid silicon targets. The rate coefficient of the reaction was derived from the decay rate of the ion signal. The measured rate coefficient is 6.27-0.52+0.68x10-10cm3s-1 at Tequiv=3.9x103K. This value is about 30% higher than the Landau-Zener calculation of Butler Dalgarno and is larger by about a factor of 3 than the recent full quantal calculation of Honvault et al. copyright 1997 The American Astronomical Society
[en] Fine structure intervals connecting n = 19 Rydberg levels of Si+ with L between 9 and 16 were measured precisely using the RESIS/microwave technique. The fine structure pattern conforms closely with that predicted by an effective potential model, and indicates a value of 11.666(4)a30 for the adiabatic dipole polarizability of the Mg-like ion, Si2+
[en] Theoretical calculations for the electron impact excitation of the ions Si II, Si III, Si IV, S II, S III, and S IV are reviewed. For each ion, the accuracy and validity of the different calculations are discussed and recommended effective collision strengths are presented. 33 refs., 9 figs., 7 tabs
[en] A new batch processing end station for ion implantation has been developed for wafers of 100 to 200 mm diameter. It usilizes a spinning disk with clampless wafer support. All wafer transport is done with backside handling and is carried out in vacuum. This end station incorporates a new dose control scheme which is able to monitor the incident particle current independently of the charge state of the ions. This technique prevents errors which may be caused by charge exchange between the beam and residual gas. The design and features of this system will be reviewed and the performance to date will be presented. (orig.)