As the scaling of the device dimensions in CMOS devices runs into physical limitations, new materials beyond Si with high electron and hole mobilities such as Ge, SiGe, and III-V materials are introduced. Challenges of CMP for these materials are reviewed in this paper. First we discussed the challenge of the new integration schemes to CMP. Loading effects can result in different growth rates for varying feature sizes, which results in a critical dimension dependent overburden. This makes it more difficult to meet the targets of the CMP process with respect to oxide loss and Ge/SiGe/III-V dishing. Secondly we discuss the challenge for the reduction of the defects during CMP for these new materials. Finally the challenge that is relevant especially for the introduction of III-V materials is studied. During the polishing of III-V materials, toxic gases as well as III-V containing liquid waste will be created. The chemical mechanism of the waste control is discussed.

Approaches to the formulation of optimal beef cattle management programs have changed significantly since they were first examined in a linear programming context in the 1950s. Models were originally designed to identify feed rations which minimize the cost of providing minimum levels of energy and selected nutrients. Subsequent efforts sought to maximize overall farm or feedlot profits, including identification of optimal feeding weights, daily gains, and ration formulations (Kearl, Harris, and Fonnesbeck; Ladd and Williams). The studies varied in attention to such details as number of head fed, variety of alternative feeds, seasonality factors, animal characteristics, and the manner in which energy requirements and appetite are modeled Wilson, and others cast the California net.

Group III-Sb compound semiconductors are promising materials for future CMOS circuits. Especially, In1-xGaxSb is considered as a complimentary p-type channel material to n-type In1-xGaxAs MOSFET due to the superior hole transport properties and similar chemical properties in III-Sb’s to those of InGaAs. The heteroepitaxial growth of In1-xGaxSb on Si substrate has significant advantage for volume fabrication of III-V ICs. However large lattice mismatch between InGaSb and Si results in many growth-related defects (micro twins, threading dislocations and antiphase domain boundaries); these defects also act as deep acceptor levels. Accordingly, unintentional doping in InGaSb films causes additional scattering, increase junction leakages and affects the interface properties. In this paper, we studied the correlations between of defects and hole carrier densities in GaSb and strained In1-xGaxSb quantum well layers by using various designs of metamorphic superlattice buffers.

The paper reports on the growth of group III-Sb’s on silicon, substrate preparation, optimization of AlGaSb metamorphic buffer, formation of defects (threading dislocations, microtwins and anti-phase boundaries) and their effect on the surface morphology and electrical properties of these high hole mobility materials for future III-V CMOS technology. Defect density was found to be 2-3x higher than in similar structures grown on GaAs, resulting in 2x higher roughness. Defects also result in background p-type doping well above 1017 cm-3 causing inversion of polarity from n-type to p-type in thin n-type doped GaSb. MOS Capacitors fabricated on these buffers demonstrate similar characteristics to higher quality GaSb-on-GaAs. The highest hole mobility obtained in a strained InGaSb QW MOS channel grown on silicon is ∼630 cm2/V-s which is ∼30% lower than similar channels grown on GaAs substrates.

The antimalarial drug artemisinin (ART) is commercially extracted from the medicinal plant Artemisia annua L. Here, we report the screening of 70 A. annua plants representing 14 diverse germplasm accessions sourced from around the world, and identify lines containing >2% ART. These extremely high-yielding individuals have been maintained as vegetative clones, and they represent promising germplasm resources for future A. annua breeding programmes.

Scanning electron microscopy and X-ray analysis are standard tools in the nanotechnology world, but access to them by students is limited by high cost and lack of equipment. For this reason, among others, we have developed an on-demand remote access system to The University Spectroscopy and Imaging Facilities (USIF) of The University of Arizona (UA), by using Quartz PCI-Taipan. In general, Taipan is an online server based program that enables spectroscopy laboratories to store, organize, and manage data as well as users. Significantly, the Taipan system allows users, operators and researches to create their own online collaborations, which will, in many ways, fuse their research and outreach efforts. Therefore, we have incorporated the Taipan software to our recently installed Hitachi S-4800 FESEM and S-3400N variable-pressure SEM. With a high-speed internet connection, from any remote setting, the system allows students real-time access to view state-of-the-art microscopes, acquire data, and interact with the instrument operator. What is more, remote users can view up to six different screens including SEM image, SEM control screen, EDS, Raman spectrum, chamber scope, and microscope room as shown in Fig. 1. This offers a significant reduction of time, travel expenses, and more importantly, equipment cost.

Lake sediments have the potential to preserve proxy records of past climate change. Organic material suitable for radiocarbon dating often provides age control of such proxy records. Six shallow freshwater lakes on the sub-Antarctic island of South Georgia were investigated for carbon reservoir effects that may influence age-depth profiles from lake sediment records in this important region. Paired samples of particulate organic matter (POM) from the water column and surface sediment (bulk organic carbon) were analyzed by accelerator mass spectrometry 14C. POM in 4 lakes was found to be in equilibrium with the atmosphere (~107% modern), whereas 2 lakes showed significant depletion of 14C. In each lake, the surface sediment ages were older than the paired POM age. Surface sediment ages showed a much greater range of ages compared to the equivalent POM ages, even for lakes located in close proximity. We conclude that sediment disturbance during coring, bioturbation, and periodic resuspension of sediments are likely factors causing the difference in the apparent age of surface sediments.