PLANAR COPPER PLATING AND ELECTROPOLISHING TECHNIQUES

Electrochemical mechanical deposition (ECMD) is a novel technique that has the ability to deposit planar conductive films on non planar substrate surfaces. This technique involves electrochemical deposition (ECD) while simultaneously polishing the substrate surface. Preferential deposition of the conductor into the cavities on the substrate surface may be achieved through two different mechanisms. The first mechanism is more mechanical in nature and it involves material removal from the top surface. The second mechanism is more chemical in nature, and it involves enhancing the deposition into the cavities where mechanical sweeping does not reach and reducing deposition onto surfaces that are swept. In this study we demonstrate that in an ECMD process, low-pressure mechanical sweeping of the wafer surface during copper plating can establish a differential in the activity of the organic accelerator species between the surface and the cavity regions of the substrate and thus give rise to bottom-up filling in even the lowest aspect-ratio cavities. Planar layers obtained by the ECMD technique have been successfully employed in an electrochemical polishing technique for stress-free removal of Cu.     

Socioeconomic Status, Resources, Psychological Experiences, and Emotional Responses: A Test of the Reserve Capacity Model.

The current study used ecological momentary assessment to test several tenets of the reserve capacity model (L.C. Gallo & K. A. Matthews, 2003). Women (N = 108) with varying socioeconomic status (SES) monitored positive and negative psychosocial experiences and emotions across 2 days. Measures of intrapsychic and social resources were aggregated to represent the reserve capacity available to manage stress. Lower SES was associated with less perceived control and positive affect and more social strain. Control and strain contributed to the association between SES and positive affect. Lower SES elicited greater positive but not negative emotional reactivity to psychosocial experiences. Women with low SES had fewer resources relative to those with higher SES, and resources contributed to the association between SES and daily experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smooth and Vertical Facet Formation for AlGaN-Based Deep-UV Laser Diodes

Using a two-step method of plasma and wet chemical etching, we demonstrate smooth, vertical facets for use in Al _x Ga_1−x N-based deep-ultraviolet laser-diode heterostructures where x = 0 to 0.5. Optimization of plasma-etching conditions included increasing both temperature and radiofrequency (RF) power to achieve a facet angle of 5 deg from vertical. Subsequent etching in AZ400K developer was investigated to reduce the facet surface roughness and improve facet verticality. The resulting combined processes produced improved facet sidewalls with an average angle of 0.7 deg from vertical and less than 2-nm root-mean-square (RMS) roughness, yielding an estimated reflectivity greater than 95% of that of a perfectly smooth and vertical facet.     

Smoking, advertising, and psychology.

J. D. Matarazzo (see record 1982-25842-001) suggested that the substantial increase in adult female smokers between 1955 and 1979 resulted from advertisements carefully crafted with the help of psychologists. The present author, however, argues that there is a more plausible explanation: During the same period, the substantial educational achievement gap between men and women was eliminated, and the attendant changes in living habits and family structure are more easily linked to the use of tobacco than are the effects of advertising promotion. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of leadership in a simulated industrial task.

Ss high and low in dominance were selected with the CPI Dominance (Do) scale and confronted with a simulated industrial task which could be solved best by 1 person assuming a leader role and the other following his instructions. When the instructions emphasized the task, the High Do Ss did not assume the leader role significantly more often than the Low Do Ss. When leadership was emphasized, however, the High Do Ss assumed the leader role in 90% of the pairs. It is concluded that the CPI Do scale has predictive validity when leadership is made salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential scanning calorimetry analysis of morphological changes in segmented elastomers

Investigations of morphological changes which are induced in segmented elastomers by annealing and quenching are reported. Four different polymers were studied each based on the same soft segment—1000 or 2000 molecular weight poly(tetramethylene oxide). The hard segments were 4,4′-diphenylmethane diisocyanate (MDI) chain extended with 1,4-butane diol (ET series), piperazine coupled with 1,4-butane diol bischloroformate (BN-1,4), or dimethyl terephthalate condensed with 1,4-butane diol (H-50). Following annealing at various temperatures (120, 150, 170, or 190°C), the polymers were quenched to ambient conditions, and their properties measured by differential scanning calorimetry (DSC) as a function of time following the quench. DSC measurements taken immediately after the quench show that the soft segment T_g is higher than that of the control, suggesting that the applied thermal history promoted increased mixing of hard and soft segments. As time passes after quenching, the T_g values decrease and approach an equilibrium value. This effect is much smaller for those samples having crystalline hard segments. Endotherms attributed to the disruption of long range ordering in the hard segment domains resulted from the annealing process. These endotherms appeared at higher temperatures for higher annealing temperatures. The positions of crystalline melting endotherms were independent of the annealing/quenching conditions investigated.     

Developmental competence of bovine embryos from heat-stressed ova

Because multiple ovulation embryo transfer procedures are occasionally performed in cows experiencing heat stress, the goal of this study was to assess the developmental competence of otherwise morphologically normal embryos from heat-stressed ova. To this end, the ability of compact morulae from heat-stressed and non-heat-stressed bovine ova to undergo blastocyst development after culture at 38.5 or 41.0°C was examined. It was hypothesized that heat-induced perturbations in the ooplasm carry over to increase the susceptibility of the preattachment embryo to heat stress. Initially, ova were matured at 38.5 or 41.0°C. The consequences of heat stress did not include altered cleavage, but did reduce the proportion of 8- to 16-cell-stage embryos (55.3 vs. 50.6%; SEM ± 1.9). Although proportionately fewer, compact morulae from heat-stressed ova were equivalent in quality to those from non-heat-stressed ova (2.1 and 2.1; SEM = 0.04). Culture of compact morulae from non-heat-stressed ova at 41.0°C did not affect blastocyst development (71.9 and 71.5%; SEM = 3.0). Furthermore, the development of compact morulae from heat-stressed ova was similar to that of non-heat-stressed ova after culture at 38.5°C (68.2 vs. 71.9 and 71.5%; SEM = 3.0). However, blastocyst development was reduced when compact morulae from heat-stressed ova were cultured at 41.0°C (62.3 vs. 71.9, 71.5 and 68.2; SEM = 3.1). In summary, reduced compaction rates of heat-stressed ova explained in part why fewer develop to the blastocyst stage after fertilization. The thermolability of the few embryos that develop from otherwise developmentally challenged ova emphasizes the importance of minimizing exposure to stressor(s) during oocyte maturation.     

Annealing-induced morphological changes in segmented elastomers

Thermal analysis has been used to study annealing-induced ordering in segmented elastomers. Twelve segmented elastomers were studied each having approximately 50% by wt hard segment content. Seven general classes of materials were examined including polyether and polyester polyurethanes, polyether polyurethane-urea, and polyether-polyester. Materials were slow cooled (?10°C min^?1) from the melt to an annealing temperature (?10°, 20°, 60°, 90° or 120°C) where they were annealed (16, 12, 8, 6 or 4 days, respectively). Annealing was followed by slow cooling (?10°C min^?1) to ?120°C after which a d.s.c. experiment was run. In general, annealing resulted in an endothermic peak at a temperature 20°–50°C above that of the temperature of annealing. This phenomenon was observed in both semicrystalline and amorphous materials. The closer the annealing endotherm was to a crystalline endotherm without exceeding it in temperature, the larger its size. Annealing endotherms resulted from hard or soft segment ordering. Only one annealing endotherm was observed for a given annealing history, even though in some materials hard and soft segments could exhibit annealing-induced morphological changes. Hard segment homopolymers were studied yielding results similar to the block polymers containing shorter sequences of the same material. This suggests that annealing-induced ordering is an intradomain phenomenon not associated with the interphase between domains, or necessarily dependent on the chain architecture of segmented elastomers.