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For all IPS drinks, the mean package size was larger than the mean serving size (mean (sd)=412 (157) ml and 359 (159) ml, respectively). The mean (sd) package size of IPS drinks was significantly different for all countries (range: Australia=370 (149) ml to New Zealand=484 (191) ml; P<0·01). The mean (sd) package size of Dutch BPS drinks (1313 (323) ml) was significantly smaller compared with the other countries (New Zealand=1481 (595) ml, Australia=1542 (595) ml, Canada=1550 (434) ml; P<0·01). The mean (sd) serving size of BPS drinks was significantly different across all countries (range: Netherlands=216 (30) ml to Canada=248 (31) ml; P<0·00). New Zealand had the largest package and serving sizes of the countries assessed. In all countries, a large number of different serving sizes were used to provide information on the amount appropriate to consume in one sitting.
At this point there is substantial inconsistency in package sizes and manufacturer-recommended serving sizes of sweet beverages within and between four high-income countries, especially for IPS drinks. As consumers do factor serving size into their judgements of healthiness of a product, serving size regulations, preferably set by governments and global health organisations, would provide consistency and assist individuals in making healthier food choices.
We study the stellar content of three galactic bulges with the high resolution gratings (R=7000) of the WiFeS integral field unit in order to better understand their formation and evolution. In all cases we find that at least 50% of the stellar mass already existed 12 Gyrs ago, more than currently predicted by simulations. A younger component (age between ∼1 to ∼8 Gyrs) is also prominent and its present day distribution seems to be much more affected by morphological structures, especially bars, than the older one. This in-depth analysis supports the notion of increasing complexity in bulges which cannot be achieved by mergers alone, but requires a non-negligible contribution from secular evolution.
Aluminum nitride (AlN) thin films were deposited from trimethyl aluminum (TMA) and Ammonia (NH3) by thermal atomic layer deposition (thermal ALD) and plasma enhanced atomic layer deposition (PEALD) on 200 mm silicon wafers. For both thermal ALD and PEALD, the deposition rate increased significantly with the deposition temperature. The deposition rate did not fully saturate even with 10 seconds of NH3 pulse time. Plasma significantly increased the deposition rate of AlN films. A large number of incubation cycles were needed to deposit AlN films on Si wafers. 100% step coverage was achieved on trenches with aspect ratio of 35:1 at 100 nm feature size by thermal ALD. X-ray diffraction (XRD) data showed that the AlN films deposited from 370 °C to 470 °C were polycrystalline. Glancing angle X-ray reflection (XRR) results showed that the RMS roughness of the films increased as the film thickness increased.
Weed seed persistence in soil can be influenced by many factors, including crop management. This research was conducted to determine whether organic management systems with higher organic amendments and soil microbial biomass could reduce weed seed persistence compared with conventional management systems. Seeds of smooth pigweed and common lambsquarters were buried in mesh bags in organic and conventional systems of two long-term experiments, the Farming Systems Project at the Beltsville Agricultural Research Center, Maryland, and the Farming Systems Trial at the Rodale Institute, Pennsylvania. Seed viability was determined after retrieval at half-year intervals for 2 yr. Total soil microbial biomass, as measured by phospholipid fatty acid (PLFA) content, was higher in organic systems than in conventional systems at both locations. Over all systems, locations, and experiments, viable seed half-life was relatively consistent with a mean of 1.3 and 1.1 yr and a standard deviation of 0.5 and 0.3 for smooth pigweed and common lambsquarters, respectively. Differences between systems were small and relatively inconsistent. Half-life of smooth pigweed seeds was shorter in the organic than in the conventional system in two of four location-experiments. Half-life of common lambsquarters was shorter in the organic than in the conventional system in one of four location-experiments, but longer in the organic than in the conventional system in two of four location-experiments. There were few correlations between PLFA biomarkers and seed half-lives in three of four location-experiments; however, there were negative correlations up to −0.64 for common lambsquarters and −0.55 for smooth pigweed in the second Rodale experiment. The lack of consistent system effects on seed persistence and the lack of consistent associations between soil microbial biomass and weed seed persistence suggest that soil microorganisms do not have a dominating role in seed mortality. More precise research targeted to identifying specific microbial functions causing seed mortality will be needed to provide a clearer picture of the role of soil microbes in weed seed persistence.
Atomic Layer Deposition (ALD) is an emerging ultra-thin film deposition technique for advanced microelectronics applications. Enabling features of ALD are precise control over film thickness, excellent conformality and relative insensitivity to wafer size. Additionally, ALD allows interface and film engineering that can be utilized to maximize device performance within the minimum feature size requirements. This paper reports on the compositional, structural and electrical properties of engineered Ti-Ta-N composite films grown by ALD at 360°C. For a wide range of composition these Ti-Ta-N films exhibit resistivity from 500 to 2000 μω-cm, high density, and 100 % step coverage. Additionally, the ability to control texture by changing film composition is established. Based on experimental results, an approach to grow Composite Engineered Barriers by ALD (CEBA) is described that could provide a solution to the challenging barrier requirements.
In the first part of this paper the role of rapid thermal annealing in sulicide processing is viewed from a theoretical point of view with respect to what is known about metal-silicon reactions. The second part is a brief survey of the quickly expanding literature on the rapid thermal annealing of silicides. Whereas RTA does not appear to solve all, or perhaps even any, of the problems encountered in the use of silicides, it is concluded that RTA presents a number of definite advantages.
This paper reports the results of a study of thin SiO2 growth and annealing in a lamp heater (Heatpulse). Good quality 5–10 mn SiO2 films on silicon have been obtained. For good oxides the average destructive breakdown- field was 13 MV/cm and very few or no low-field breakdowns were found. The breakdown statistics were obtained with Al gate capacitors and by a current staircase-ramp technique which is described in the paper. Processing with a single oxidation step, oxidationannealing, and oxidation-annealing-oxidation are discussed.
Pyrometers are used to measure wafer temperature in rapid thermal processors. This paper focuses on the effect of thin dielectric films on the accuracy of pyrometric temperature measurement. The thin films affect the emissivity of the wafer, which in turn affects the radiation emitted by the wafer. Wafers with different oxide thicknesses were monitored by both pyrometer and thermocouple. Temperature errors of the order of 10°C to 50°C were found for wafers of differing oxide thicknesses. The chamber reflectivity was found to be an important factor in determining the ‘effective’ emissivity of the wafer. Pyrometer recalibration is necessary to accurately measure wafer temperature.
The reverse annealing of ion implanted boron, namely, the decrease in the concentration of electrically active boron as the isochronal annealing temperature increases, occurs in the temperature range from 550 to 650°C during conventional furnace heating. In this study, silicon crystals were boron implanted at 50 Kev to a dose of 1×1015 cm-2 followed by both furnace and tungsten-halogen lamp annealing in the reverse annealing temperature range. Cross-sectional Transmission electron microscopic (TEM) technique was used to examine the microstructural changes during annealing as a function of depth. Sheet resistance measurements gave a quick check of the electrical properties, while spreading resistance profiling with shallow angle lapping and Hall measurements reveals the mobility and carrier concentration as a function of depth. Czochralski and Float Zone crystals were studied to examine the effect of oxygen. Tungsten-halogen lamp thermal processing was found to have a more pronounced effect on the annealing of secondary defects than did furnace annealing. The reverse annealing of boron was eliminated completely for lamp annealing time as short as 60 seconds.
The rapid thermal annealing (RTA) of p+n and n+p diodes, fabricated by the LOCOS process, and its subsequent effects on junction leakage current, junction depth and dopant activation were investigated. The reverse bias diode leakage currents of implanted Si <100> samples (As+: 60 KeY, 5×1014 5×1015 cm−2, B+: 25 KeV, l×1014, l×1015 cm−2 and BF2+: 45 KeV, 1×1015cm−2 ) were measured as functions of annealing temperature, and dwell time. The annealing was performed using an Eaton RTA system (Nova ROA-400) at temperatures ranging from 950 °C to 1150 °C. Annealing times ranged from 0.2 sec. to 10 sec. The results from the diode leakage current analysis are correlated with those from Secondary Ion Mass Spectroscopy (SIMS) and differential Hall measurements. The reverse-biased leakage currents from the RTA-treated samples are compared with those from furnace-annealed samples.
The annealing behavior of B or N dual implants in 1-SiC thin films has been studied using cross-sectional transmission electron microscopy (XTEM), secondary ion mass spectroscopy (SIMS), and four point probe electrical measurements. A high resistivity layer was produced after annealing the B implanted-amorphous layer in the temperature range from 1000°C to 1500°C for 300 a; however, the resistivity rapidly decreased as a result of annealing at higher temperatures. The reasons for these changes in resistivity and the lack of p-type conduction at all annealing temperatures in these B implants include: (1) possible compensation of the native n-type carriers, (2) reduction in the B concentration via formation of B-containing precipitates between 1300°C and 1600°C and out diffusion of this species at and above 1600°C, and (3) creation of additional n-type carriers.
No precipitates or defect structure was observed in N implanted-annealed samples. The resistivity of this non amorphous n-type layer decreased with increasing annealing temperatures from 700°C to 1800°C. Furthermore n-p junction diodes were fabricated for the first time in β-SiC via N implantation into samples previously in situ doped with 8 × 1018/cm3 Al coupled with rapid thermal annealing at 1200°C for 300 a. A typical diode ideality constant and a saturation current for these diodes was 3.4 and 9 × 10-10 A/cm2, respectively.
The effects of implanting Se+ ions through Si N4 layers have been compared with implants into uncapped GaAs. Through nitride implants have a higher residual damage, lower carrier concentration and lower mobility following rapid thermal annealing between 850 and 975 °C. The effect is believed to be due to the interface strain between the encapsulant and the amorphous GaAs.
Single crystal silicon wafers have been oxidised by exposure to an oxygen ambient at atmospheric pressure during RTP using an A G Associates Heatpulse 2101 Rapid Thermal Annealer. Wafers of the standard orientations used in silicon device processing <100>, <111> and <110> were studied. Oxidation was carried out in the temperature range 900 to 1250°C for times of RTP from 4 to 25U seconds producing oxides up to 60nm in thickness. Oxidation rates and their orientation and temperature dependence were derived from ellipsometric measurements of oxide thickness. X-ray photoelectron spectroscopy (XPS) and infra-red absorption spectrophotometry were also employed in the oxide characterisation. Preliminary electrical characterisation of the oxides, investigated using MOS C-V analyses, showed that the interface state densities were comparable to those in conventional furnace grown oxides.
This bibliography presents 342 references to work published on rapid thermal processing (RTP) from 1979 through mid-1985. A variety of broad-beam energy sources are represented, including: arc and quartz-halogen lamps, blackbody radiators, strip heaters, broadly rastered electron beams, and defocused CO2 lasers. Citations were obtained by both manual searching and searching of a commercially available computerized data base (I NSPEC). Entries are grouped under 13 topical headings: reviews, implanted dopant activation and diffusion in silicon, polycrystalline silicon, silicides and polycides, metals, dielectrics, compound semiconductors, defects and microstructure, device applications (silicon and compound semiconductors), miscellaneous applications, equipment, and modeling. Within each group, citations are arranged alphabetically by title. A full author index is provided.
The characterization of microstructures is fundamentally important to investigations of amorphization which is induced by ion implantation and recrystallization which occurs by solid-phase, epitaxial regrowth. In this paper, microstructures of amorphized, partially regrown and fully regrown layers are described in terms of extended-defect states of the material. Initial states (i.e. amorphized) and final states (i.e. solid-phase regrown and then reordered) are defined. Transmission electron microscopy and Rutherford backscattering/ion-channeling are the analytical techniques which are used in the characterization.
Polycrystalline silicon films were transient preannealed, As implanted, and transient post-annealed at peak temperatures up to 1250°C for times up to 17.5 seconds. Structural changes occurring during post-annealing were examined by transmission electron microscopy. These results were correlated to Rutherford Backscattering and sheet resistance results. The grain size, which increased from 5–20 to 150–300 nm during preannealing, did not increase during post-annealing. During early stages of post-annealing, As diffused along grain boundaries and generated dislocation sources at grain boundary surfaces. Subsequently, as annealing progressed, a fine, As-rich cellular network structure propagated into the grains until the structure of an entire grain was transformed into a fine cellular network at the longest annealing times. Residual stresses in the film were relieved during formation of the network structure. The sheet resistance of preannealed samples, in comparison with non-preannealed samples with similar implantation and final transient anneals, was lower at shorter annealing times due to the larger grain size, which increased mobility, and the reduced grain boundary area, which trapped less As. It was also lower at longer annealing times due to the formation of the cellular network structure. In subsequent furnace stability tests for 30 minutes at 700–900°C, the sheet resistance increased less for preannealed than for non-preannealed samples.