Growth characteristics of graphene synthesized via chemical vapor deposition using carbon tetrabromide precursor

A carbon tetrabromide (CBr4) precursor was employed for the chemical vapor deposition (CVD) of graphene, and the graphene growth characteristics as functions of the following key factors were then investigated: growth time, growth temperature, and the partial pressure of the precursor. The graphene was transferred onto a SiO2/Si substrate and characterized using transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy, and the electrical properties were measured through the fabrication of field-effect transistors. Our results show that high yield and controllable growth are possible via CVD used with a CBr4 precursor. Thus, CBr4 precursor is a new alternative candidate for use in the mass production of graphene. (C) 2015 Elsevier B.V. All rights reserved

The effects of nitrogen incorporation on the properties of atomic layer deposited Ru thin films as a direct-plateable diffusion barrier for Cu interconnect

N-incorporated Ru films were deposited by atomic layer deposition (ALD) at a deposition temperature of 270 degrees C using 1-isopropyl-4-methylbenzene-cyclohexa-1,3-dienyl ruthenium and N-2/H-2 mixture plasma as the precursor and reactant, respectively. The N content in the ALD-Ru films was controlled by changing the gas ratio [N-2 versus the total gas (N-2 + H-2) flow rates] in the reactant from 0.82 to 1. Secondary ion mass spectrometry depth profiling revealed an increase in N content in the film with increasing gas ratio. The amount of N in the ALD-Ru films had a considerable effect on the film properties, such as resistivity, crystallinity and microstructure. Although the resistivity of the pure ALD-Ru film was similar to 19 mu Omega cm, the N-incorporated ALD-Ru films deposited with a gas ratio of 0.86 (N/Ru: similar to 0.38) showed a resistivity of similar to 340 mu Omega cm, which increased continuously with increasing gas ratio. X-ray and electron diffraction revealed degradation in film crystallinity and decrease in grain size with increasing N incorporation into ALD-Ru films. Transmission electron microscopy showed that N-incorporated ALD-Ru films formed nanocrystalline and non-columnar grain structures. This is in contrast to that observed in the pure ALD-Ru film, which had a polycrystalline columnar grain structure. The growth rate of a representative N-incorporated Ru film deposited with a gas ratio of 0.86 showed a linear dependency on the number of ALD cycles; growth rate of 0.051 nm/cycle at short incubation cycles of similar to 3. The step coverage was approximately 98% over the trench structure (aspect ratio: 4.5) with a top opening width of 25 nm. The direct plating of Cu on an optimized N-incorporated ALD-Ru film (5 nm in thickness) was possible. The structure of Cu (80 nm)/N-incorporated ALD-Ru (8 nm)/Si was found to be stable without the formation of copper silicide after annealing at 600 degrees C for 30 min. (C) 2014 Elsevier B.V. All rights reserved

Atomic layer deposition of Ru thin film using N-2/H-2 plasma as a reactant

Ruthenium (Ru) thin films were grown by atomic layer deposition using IMBCHRu [(eta 6-1-Isopropyl-4-MethylBenzene)(eta 4-CycloHexa-1,3-diene)Ruthenium(0)] as a precursor and a nitrogen-hydrogen mixture (N-2/H-2) plasma as a reactant, at the substrate temperature of 270 degrees C. In the wide range of the ratios of N-2 and total gas flow rates (fN(2)/N-2+H-2) from 0.12 to 0.70, pure Ru films with negligible nitrogen incorporation of 0.5 at.% were obtained, with resistivities ranging from similar to 20 to similar to 30 mu Omega cm. A growth rate of 0.057 nm/cycle and negligible incubation cycle for the growth on SiO2 was observed, indicating the fast nucleation of Ru. The Ru films formed polycrystalline and columnar grain structures with a hexagonal-close-packed phase. Its resistivity was dependent on the crystallinity, which could be controlled by varying the deposition parameters such as plasma power and pulsing time. Cu was electroplated on a 10-nm-thick Ru film. Interestingly, it was found that the nitrogen could be incorporated into Ru at a higher reactant gas ratio of 0.86. The N-incorporated Ru film (similar to 20 at.% of N) formed a nanocrystalline and non-columnar grain structure with the resistivity of similar to 340 mu Omega cm. (C) 2012 Elsevier B. V. All rights reserved

Lesson learned from peer volunteers in a peer-led pain management program among nursing home residents

Background: Chronic pain is common among older adults and is associated with adverse physical and psychological outcomes. Given the burden of pain and limited healthcare resources, devising innovative and cost-effective ways of managing chronic pain is of high priority. The aim of this paper is to explore the experiences and perceptions of peer volunteers (PVs) in a peer-led pain management program among nursing home residents in Hong Kong. Methods: Forty-six PVs were recruited and trained to lead a pain management program (PAP). The PAP consisted of one 1 hour session per week for 12 weeks. It included 20 min of physical exercises performed under the supervision of PVs, followed by 30 min of pain management education, including information on pain situations, the impacts of pain, the use of drugs and non-drug strategies for pain management, demonstrations, and return demonstrations of various non-drug pain management techniques. Quantitative data were collected from questionnaires (demographics, pain situation, and pain knowledge) for all PVs. Qualitative data (PVs’ experiences in leading the PAP, their perceived benefits, barriers encountered, and recommendations for improving the PAP) were collected at week 12 (upon completion of the PAP). Data were analyzed using the Statistical Package for Social Sciences and content analysis for qualitative data. Results: A total of 46 PVs were recruited (34 females, 74%), with a mean ± SD age of 61.0 ± 5.1 years. Thirty-one of them reported having chronic pain. Before the training, their self-rated pain knowledge was 40.0 ± 20.5 (maximum 100 points) while their actual pain knowledge score was 86.1 ± 10.6 (maximum 100 points). The PVs reported an improvement in their knowledge and skills after leading PAPs. No PVs reported having received any negative comments about their role in leading the PAP but mentioned that they had received feedback on how to improve the program. Conclusions: This study provides further evidence that peer-led pain management programs are feasible and can lead to positive experiences for the PVs. Peer support models are coming into wide use because they show promise in helping patients to manage chronic conditions. Peer volunteers will become important resources in elderly care. The barriers that were identified may lead to improvements in the design and planning of future PAPs

Changes in Osteoblastic Activity in Patient Who Received Bortezomib as Second Line Treatment for Plasma Cell Myeloma: A Prospective Multicenter Study

We conducted a prospective multicenter study identifying the role of bortezomib in patients with relapsed or refractory plasma cell myeloma (PCM) in bone resorption and formation via bone turnover markers. A total of 104 patients received at least 1 cycle of bortezomib. Most of them had advanced disease (n=89). Among them, 75 patients completed 4 cycles of treatment. Most of the patients (81.7%) were treated in combination with steroid. After the 4th cycle treatment, 47 of 75 patients achieved CR, nCR, VGPR, and PR (64.4%), while 26 patients achieved less than PR (35.6%). The proportion of patients who achieved ≥ PR increased as patients received more treatment cycles, reaching 90% after the 8th cycle. DKK-1 levels decreased significantly posttreatment. Bone formation markers (bALP and OC) and osteoclast regulator such as sRANKL also decreased significantly. These findings were observed primarily in patients who received steroid and who had a longer disease duration. While sRANKL demonstrated significant reduction posttreatment, osteoprotegerin (OPG) level did not significantly change posttreatment, resulting in a decreased sRANKL/OPG ratio (P=0.037). In conclusion, our clinical data suggest that treatment with bortezomib and steroid may rearrange the metabolic balance between osteoblast and osteoclast activities in PCM