729 research outputs found

    Highly conductive Sb-doped layers in strained Si

    Get PDF
    The ability to create stable, highly conductive ultrashallow doped regions is a key requirement for future silicon-based devices. It is shown that biaxial tensile strain reduces the sheet resistance of highly doped n-type layers created by Sb or As implantation. The improvement is stronger with Sb, leading to a reversal in the relative doping efficiency of these n-type impurities. For Sb, the primary effect is a strong enhancement of activation as a function of tensile strain. At low processing temperatures, 0.7% strain more than doubles Sb activation, while enabling the formation of stable, ~10-nm-deep junctions. This makes Sb an interesting alternative to As for ultrashallow junctions in strain-engineered complementary metal-oxide-semiconductor device

    'Don't you know that it's different for girls': a dynamic exploration of trust, breach and violation for women en route to the top

    Get PDF
    This is the author accepted manuscript. The final version is available from Edward Elgar Publishing via the link in this recordKPM

    An effective electrical isolation scheme by iron implantation at different substrate temperatures

    Get PDF
    High-energy implantation of iron in n-type doped InP epilayers at different substrate temperatures: 77K, room temperature (RT), 100degreesC and 200degreesC was investigated to study the electrical isolation of n-type InP. Iron isolation implants were performed at 1MeV with a fluence of 5 x 10(14) /cm(2). This isolation scheme was chosen to place most of the iron atoms well inside the n-type doped layer. The sheet resistivity (R,), sheet carrier concentration (n(S)) and sheet mobility (p) were measured as a function of substrate temperature and post-implantation annealing temperature (100 - 800degreesC). Samples implanted at 77K, RT and 100degreesC show more or less the same trend of postimplant annealing characteristics. A maximum sheet resistivity of similar to1 x 10(7) Omega/rectangle was achieved for samples implanted at 77K, RT and 100degreesC after annealing at 400degreesC. A lower resistivity of similar to1 x 10(6) Omega/rectangle was obtained for a 200degreesC implant after annealing at 4000C. Lower damage accumulation due to enhanced dynamic annealing is observed for the highest implantation temperature. For 200degreesC substrate temperature, annealing above 4000C resulted in a gradual decrease in sheet resistivity to a value close to that of the starting material. But this is not the case for the lower substrate temperatures. The sheet resistivity was increased again for 77K, RT and 100()C implant after annealing at 600degreesC. We infer that for 77K, RT and 100degreesC implantation temperatures, the electrical isolation is due to a product of both damage related centers and defects related to the presence of Fe whereas for 200degreesC substrate temperature, we infer that only damage induced compensation removes the carriers. These results show the importance of iron implants as a device isolation scheme.</p

    Pulsed Laser Cutting of Magnesium-Calcium for Biodegradable Stents

    Get PDF
    There is growing interests in the use of biodegradable magnesium implants for cardiovascular and pulmonary applications such as stents. Magnesium is a metal that has the ability to gradually dissolve and absorb into the human body after implantation. There is very little work discussing the relationship between process parameters and cut quality of magnesium stents by laser cutting. The objective of this research is to determine the effect of laser cutting conditions including peak laser power and cutting speed of a millisecond range pulsed laser on kerf geometry, surface topography, surface roughness, and microstructure. An assessment on the experimental work discussing laser cutting of magnesium alloys is also presented

    Health Disparities in Liver Cancer: An Analysis of the Ohio Cancer Incidence Surveillance System

    Get PDF
    Background: We explored associations between neighborhood deprivation and tumor characteristics, treatment, and 5-year survival among primary hepatocellular carcinoma (HCC) patients in Ohio diagnosed between 2008 and 2016. Methods: We used data from the Ohio Cancer Incidence Surveillance System and limited our analysis to adult (&gt;18 years of age) HCC patients with known census tract information based on address at diagnosis. Using principal components analysis, we created a neighborhood deprivation index (NDI) using 9 census tract-level variables. We examined associations between tumor characteristics (stage and tumor size) and NDI quintile using chi-square tests and analysis of variance (ANOVA). Associations between guideline-concordant care and NDI using log-binomial regression adjusted for sex, race, age at diagnosis, metropolitan status, cancer stage, and year of diagnosis were conducted. For 5-year survival, we utilized Cox proportional hazards models with a similar adjustment set. Results: Neighborhood deprivation index was not associated with stage or tumor size. Individuals living in the most deprived neighborhoods were 16% less likely to receive guideline-concordant care as compared to individuals living in the least deprived neighborhoods (adjusted prevalence ratio [PR]: 0.84; 95% confidence interval [CI]: 0.74-0.94). Similarly, individuals living in the most deprived neighborhoods were 15% less likely to survive 5 years compared to individuals living in the least deprived neighborhoods (adjusted Hazard Ratio: 1.15; 95% CI: 1.01-1.29). Conclusion: Our results suggest a negative association between neighborhood deprivation on guideline-concordant care and survival among HCC patients. Interventions targeting disparities of HCC should focus not only on individual-level factors but address larger neighborhood level factors as well

    Ultrastructural Study of Yam Tuber as Related to Postharvest Hardness

    Get PDF
    Usually, parenchyma cell walls of monocotyledons do not develop secondary walls; however a few days after harvesting, the yam tuber of Dioscorea dumetorum starts to harden. Two or three weeks Iater, hardness is so pronounced that the tubers cannot be eaten, even after a long cooking time. Cytochemical studies using autofluorescence or some fluorescent dyes, such as phloroglucinol hydrochloride showed that the thin, and flexible cell walls of parenchyma tubers very quickly became fully lignified after harvesting. Ultrastructura 1 stud ies of the hardened ce 11 wa 11 s showed very thick secondary wa 11 s and very deep pit apertures. These secondary walls reacted strong ly with li gn in reactants such as potassium permanganate. The use of a radioactive (l \u27• C) ce llulose precursor, uri dine- 5\u27-d ipho sphateglucose, confirmed the formation of such secondary walls. The lignification started from the corners of the cells around intercellular spaces and proceeded along the walls

    Benchmark Burnishing with Almen Strip for Surface Integrity

    Get PDF
    Burnishing is a surface treatment process widely used in aerospace, navy and other industries to improve fatigue and corrosion resistance by introducing a compressive residual stress layer. The measurement of residual stress by XRD is expensive, time consuming, and tedious. This work presented a quick method to determine the residual stress by using Almen strips. Inspired by the application of Almen strips in shot peening, deflections of burnished Almen strips under different burnishing conditions were measured. It was found that the deflection of Almen strip reflects the magnitude and penetration depth into subsurface of induced stress. Higher burnishing force, smaller feed, and smaller ball diameter tend to produce more deflection, which indicates more compressive residual stress

    Social Attitudes of Field Instructors

    Get PDF
    In both the classroom setting and field practicum, social work students begin to develop competence in practice with diverse populations. Field instructors play a critical role in educating students on diversity issues and preparing students to practice without bias. A cross-sectional study was conducted to better understand social attitudes of field instructors participating in a Seminar in Field Instructor (SIFI) training (N=88). The field instructors had generally positive attitudes. Results indicated that field instructors’ comfort level and demographic variables were predictors of social attitudes. Implications for social work field instruction are discussed
    corecore