A5083484684- Plasma Diagnostics and Applications
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Copper Interconnects and Reliability
- Rangeland Management and Livestock Ecology
- Ecology and Vegetation Dynamics Studies
- Sustainable Agricultural Systems Analysis
- Ruminant Nutrition and Digestive Physiology
- Pasture and Agricultural Systems
- Plasma Applications and Diagnostics
- Rangeland and Wildlife Management
- Forest Management and Policy
- Botany and Plant Ecology Studies
- Agriculture and Rural Development Research
- Electrostatic Discharge in Electronics
- Laser-induced spectroscopy and plasma
- Ecology and biodiversity studies
- Soil erosion and sediment transport
- Catalytic Processes in Materials Science
- Agricultural Systems and Practices
- Genetic and phenotypic traits in livestock
- Electrohydrodynamics and Fluid Dynamics
- Effects of Environmental Stressors on Livestock
- Ferroelectric and Negative Capacitance Devices
- Advancements in Semiconductor Devices and Circuit Design
Scotland's Rural College
2005-2023
Lam Research (United States)
1993-2015
Lam Research (Austria)
1999-2014
Yale University
2010
Holland Hospital
2010
Applied Materials (United States)
2001-2007
University of California, Davis
1988
Texas A&M University
1981
Inductively coupled plasma (ICP) etching reactors are rapidly becoming the tool of choice for low gas pressure, high density semiconductor materials. Due to their symmetry excitation, these devices tend have quite uniform etch rates across wafer. However, side and azimuthal variations in been observed, attributed various asymmetries pumping, reactor structure coil properties. In this article, a three-dimensional computer model an ICP is reported whose purposes investigate asymmetries. The...
Argon plasma characteristics in a dual-frequency, capacitively coupled, 300 mm-wafer processing system were investigated for rf drive frequencies between 10 and 190 MHz. We report spatial frequency dependent changes parameters such as line-integrated electron density, ion saturation current, optical emission argon metastable density. For the conditions investigated, density was nonlinear function of at constant power. In addition, distribution positive ions changed from uniform to peaked...
Anisotropic etching, enabled by energetic ion bombardment, is one of the primary roles plasma–assisted materials processing for microelectronics fabrication. One challenge in plasma etching being able to control energy-angular distributions (IEADs) from presheath surface wafer which necessary maintaining critical dimension features. Dual frequency capacitive coupled plasmas (DF-CCPs) potentially provide flexible IEADs, providing high selectivity while different and improved uniformity across...
From grazing lands to meat packing, beef production systems in the United States are increasingly expected meet new global demand without compromising environmental quality. These challenges and opportunities manifest American Southwest Ogallala Aquifer region, neighboring regions connected ecologically socially through production. Each year most calves raised on extensive, arid Southwestern pastures exported region for finishing grains from Upper Midwest. Intensifying changes climate,...
A transformer coupled plasma (TCP) source has been integrated into a production tool and characterized for subhalf micron etching of thin films. planar 13.56 MHz is produced over wide pressure range 1–500 mTorr. Langmuir probe measurements below 10 mTorr show ion densities ≳1012 cm−3 low potentials. These properties are favorable high etch rates damage to device structures. Radio-frequency power also supplied the wafer electrode dc bias control. Separation generation functions allows control...
There is much interest in scaling rf-excited capacitively coupled plasma reactors to larger sizes and higher frequencies. As the size approaches operating wavelength, concerns arise about non-uniformity across work piece, particularly light of well-documented slow-surface-wave phenomenon. We present measurements calculations spatial frequency dependence rf magnetic fields inside argon an industrially relevant, 300 mm plasma-processing chamber. The results show distinct differences...
Synopsis In salt‐affected agriculture, the tolerance of crops for sodium depends on level salinity, and salinity in growth medium.
Process variation with chamber surface condition in high density plasma reactors can seriously affect the process performance and productivity of device manufacturing. In this work, impact coating on polycrystalline-silicon (polysilicon) gate etching Cl2- HBr-based has been studied. The dependence sensitivity to various processing conditions characterized mechanism shift analyzed. Based experimental results, root cause attributed change recombination rate free radicals different surfaces...
A dual frequency rf sheath is analyzed using a simple model to study the interaction between two driving currents and their effect on parameters. symmetric discharge with defined electron density dc potential modeled sharp boundary approximation. Three results of this are reported: (1) reproduction trends in ion energy distribution functions predicted measured previous studies, (2) frequency-mixing-dependent relationship applied potential, (3) an additional asymmetry function generated by...
Energy disposal to the CO product formed upon 351 nm photodissociation of W(CO)6 has been monitored using method time-resolved infrared laser absorption spectroscopy. The nascent can be characterized by effective vibrational, rotational, and translational temperatures; Tv=1080±60 K, T0r(v=0)=560±50 T0t(v=0 J=10) =1550±200 K. These results are considered in light various models for energy photofragmentation reaction. Vibrational is consistent with a modified version phase space theory termed...
As a result of the European Community Common Agricultural Policy reform in 2005 it is predicted that livestock grazing Scottish uplands will become less intensive. At each two upland research centres, large (>40ha) plots were established to investigate relationship between intensity and biodiversity. One plot was grazed intensively by sheep while otherwas extensively. Ground beetleswere sampled pitfall trapping determine influence pressure on ecologicalmake-up ground beetle assemblages....
Virtual fencing systems have emerged as a promising technology for managing the distribution of livestock in extensive grazing environments. This study provides comprehensive documentation learning process involving two conditional behavioral mechanisms and efficient, effective, safe animal training virtual fence applications on nursing Brangus cows. Two hypotheses were examined: (1) animals would learn to avoid restricted zones by increasing their use containment within polygon, (2)...
Objective: To ensure that revisions to the second edition of American College Occupational and Environmental Medicine (ACOEM) guidelines are as valid useful possible. Methods: The ACOEM Guideline Methodology Committee searched synthesized evidence-based medicine literature on systematic review guideline development. resulting process tools were tested during revision, changes made process. Results: methodology specifies problem formulation, search methods, screening studies, quality rating,...
Abstract A novel system combining hill sheep production with native woodland creation has been established in a Scottish mountain valley. This involved implementing an off-wintering regime for Blackface ewe flock, fencing approximately one-quarter of the valley, and planting trees within fenced area. Comparisons between initial bio-economical modelling results actual monitored data over five years were made, to assess potential success such combined terms flock economics, local labour,...
An array of novel hollow cathode plasma sources 4 mm diameter and driven by up to 500 W 13.56 MHz rf power was constructed. It investigated using spatially resolved Langmuir probe measurements in the expansion region. Initial results suggest observed downstream is combination a diffusion from exit orifice 30 long cylindrical source region uniform created By measuring ion density plumes produced two or more active sources, their mutual interaction has been inferred with aim determining...
The radial distribution of the measured voltage drop across a sheath formed between 300mm electrode and an argon plasma discharge is shown to depend on excitation radio frequency, under constant power pressure conditions. At lower frequency 13.56MHz, uniform electrode, while at higher frequencies 60 162MHz becomes radially nonuniform. magnitude spatial extent nonuniformity become greater with increasing frequency.
Abstract The aims of this study were to examine the effect three grazing treatments (year‐round stocking rates 0·8 ewes ha −1 , 0·5 and plus cattle in summer), imposed for 4 years, on herbage mass surface height a Nardus stricta ‐dominated grassland western Scotland obtain estimates annual productivity grassland. comprised proportionately 0·20 area. Stocking rate sheep had no significant first 2 years experiment, although mean summer pasture heights significantly higher under lower sheep....