On 4 July 2005 at 5:52 UT the Deep Impact mission successfully completed its goal to hit the nucleus of 9P/Tempel 1 with an impactor, forming a crater on the nucleus and ejecting material into the coma of the comet. NASA's Submillimeter Wave Astronomy Satellite (SWAS) observed the 110–101 ortho-water ground-state rotational transition in Comet 9P/Tempel 1 before, during, and after the impact. No excess emission from the impact was detected by SWAS and we derive an upper limit of 1.8×107kg on the water ice evaporated by the impact. However, the water production rate of the comet showed large natural variations of more than a factor of three during the weeks before and after the impact. Episodes of increased activity with QH2O∼1028molecules−1 alternated with periods with low outgassing (QH2O≲5×1027molecules−1). We estimate that 9P/Tempel 1 vaporized a total of N∼4.5×1034 water molecules (∼1.3×109kg) during June–September 2005. Our observations indicate that only a small fraction of the nucleus of Tempel 1 appears to be covered with active areas. Water vapor is expected to emanate predominantly from topographic features periodically facing the Sun as the comet rotates. We calculate that appreciable asymmetries of these features could lead to a spin-down or spin-up of the nucleus at observable rates.

The hyperfine interaction of phosphorus donors in fully strained Si thin films grown on virtual Si(1-x)Ge(x) substrates with x< or =0.3 is determined via electrically detected magnetic resonance. For highly strained epilayers, hyperfine interactions as low as 0.8 mT are observed, significantly below the limit predicted by valley repopulation. Within a Green's function approach, density functional theory shows that the additional reduction is caused by the volume increase of the unit cell and a relaxation of the Si ligands of the donor.

We use the Barnard 68 dark globule as a test case for a spherically symmetric PDR model exposed to low-UV radiation fields. With a roughly spherical morphology and an accurately determined density profile, Barnard 68 is ideal for this purpose. The processes governing the energy balance in the cloud surface are studied in detail. We compare the spherically symmetric PDR model by Stoerzer, Stutzki Sternberg (1996) to observations of the three lowest rotational transitions of 12CO, 13CO J = 2-1 and J = 3-2 as well as the [CI] 3P_1-3P_0 fine structure transition. We study the role of Polycyclic Aromatic Hydrocarbons (PAHs) in the chemical network of the PDR model and consider the impact of depletion as well as of a variation of the external FUV field. We find it difficult to simultaneously model the observed 12CO and 13CO emission. The 12CO and [CI] emission can be explained by a PDR model with a external FUV field of 1-0.75 chi_0, but this model fails to reproduce the observed 13CO by a factor of 2. Adding PAHs to the chemical network increases the [CI] emission by 50 reduces the 12CO and 13CO line intensity (by <10 Predictions for the [CII] 2P_3/2-2P_1/2, [CI] 3P_2-3P_1 and 12CO J= 5-4 and 4-3 transitions are presented. This allows a test of our model with future observations (APEX, NANTEN2, HERSCHEL, SOFIA).

The effect of in situ chemical HCl etching of Si(001) substrates on the relaxation behavior of CVD-grown epitaxial Si0.77Ge0.23 films is studied by high-resolution X-ray diffractometry, atomic force microscopy, and etch pit delineation experiments. The intentionally induced, moderate interface roughness leads to a slight increase of the critical layer thickness as well as to a distinctly retarded relaxation for partly relaxed films on etched compared to non-etched substrates. Both effects are found to be caused by suppressed dislocation formation rather than by reduced dislocation glide. Since the etching procedure shows no detrimental effect on the crystal quality, a related process may be applied for the stabilization of epitaxial SiGe films with higher Ge contents, e.g. for the fabrication of the next generation SiGe HBTs.

We present an improved version of rat4com, a radiation transfer model for water rotational line emission in cometary coma. The original model is limited to the rotational transitions of ortho-water for a comet with a constant water production rate (Bensch & Bergin, 2004). With the improved version of rat4com we include para-water levels and study the impact of ne,er, more accurate water-electron collision rates on the predicted line emission. Additionally, we present results for a model where the water production rate is temporarily elevated. It is an initial attempt to model the emission of a comet undergoing an outburst. The prospects of water rotational line observations with HIFI on the Herschel Space Observatory are discussed.

Using LPCVD epitaxy on 200mm standard wafers high quality strained Si/SiGe substrates (sSi/SiGe) based on a graded buffer approach have been developed. Physical and chemical analysis of the substrates, show an efficient amount of relaxation of the SiGe buffer and a fully strained silicon cap. Process integration of test devices into the sSi/SiGe layers was performed using a simply modified CMOS process. NMOS and PMOS transistors were integrated together with PIN diodes in a single sSi/SiGe substrate using the same process flow. Electrical measurements showed the enhancement of charge carrier mobility of up to 80% for electrons and 37% for holes compared to epitaxially grown silicon for reference. Also an enhanced photo responsivity at a wavelength of 1310nm for PIN diodes integrated into the SiGe buffers was demonstrated. Low leakage currents of the PIN diodes conclude good crystal quality of the SiGe buffer layer. .

The process integration of infrared-sensitive PIN photodiodes and CMOS transistors in a single 200mm SiGe substrate is reported in this paper. Si0.76Ge0.24 virtual substrates with a strained Si layer were manufactured in a LPCVD epitaxy reactor. The strained silicon layer enhances the electron mobility in NMOS transistors and the hole mobility in PMOS transistors. The lower bandgap of the Si0.76Ge0.24 material improves the infrared responsivity of the PIN photodiodes at wavelengths up to 1310nm. Results of process integration and electro-optical characterization of the manufactured devices are shown in this paper.

We present a survey of the [CI] P-3(1) --> P-3(0) fine-structure transition made with the Submillimeter Wave Astronomy Satellite, SWAS, towards translucent and dark clouds in the interstellar radiation field, ISRE. The SWAS data, is supplemented by ground-based observations of the three lowest rotational transitions of (CO)-C-12 and (CO)-C-13. The comparison of the observed [CI]/CO line ratios with current photo-dominated region (PDR) models shows that the models consistently suggest a high gas volume density of n > 10(5) cm(-3) throughout the observed region. This density is uncomfortably high for a translucent molecular cloud. PDR models with the dense clumps being embedded in a low-density (n(ic) < 10(3) cm(-3)) inter-clump medium with a modest H-2 column density of N-ic (H-2) less than or similar to (0.5-1) x 10(20) cm(-2), in contrast, match the observed line ratios for much lower densities, n less than or similar to 10(4) cm(-3).

The application of Raman spectroscopy and spectroscopic ellipsometry (SE) for characterization of strained silicon layers on SiGe virtual substrates is demonstrated. X-ray diffraction measurements (XRD) for calibration of Raman results have been carried out on strained Si/SiGe structures. For the composition-dependent shift of the Si–Si vibration in SiGe the relation ωSi–Si=520.6-68xGe is found, the strain shift coefficient for the longitudinal optical phonon in Si is estimated as −750cm−1. Three different samples with strained-Si layers on step-graded SiGe profiles with nominal final Ge concentrations in the range from 10% to 24% were investigated by XRD, transmission electron microscopy, Raman spectroscopy and SE to determinate the parameters Si cap thickness, strain in the Si layer, Ge content and relaxation of the SiGe film. A good correspondance of the results from all techniques is found.

Experiments on in situ chemical etching of strained-Si films with gaseous HCl in a commercial CVD reactor are reported. After growth of a virtual Si1−xGex substrate and the deposition of a strained-Si cap layer HCl is applied at 800°C. A pronounced dependence of the average etch rate on the strain of the Si cap layer is observed. Furthermore, the etch process is sensitive to crystal defects, leading to etch pits at the site of threading dislocations. This kind of defect etching allows to characterize the number and distribution of threading dislocations on the whole wafer area (e.g. 200mm) without additional equipment costs.