Copper Bottom-Up Filling by Electroplating Without any Additives on Patterned Wafer

In conventional Cu electroplating, various additives are used to fill pattern without defects in patterned wafers. Pulse plating and electrochemical oxidation were used to deposit Cu without any additives. Defects such as voids and seams were generated if only pulse plating was carried out. Electrochemical oxidation was performed to remove Cu metal containing defects and to remain Cu species only at the bottom part of the trenches. Then, defect free Cu films could be obtained when Cu electroplating without additives was performed on the etched substrate.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage RCECS , also by the Institute of Chemical Processes ICP in Seoul National University

Ruthenium Bottom Electrode Prepared by Electroplating for a High-density DRAM Capacitor

The possibility of Ru electroplating for application as the bottom electrode in high density dynamic random access memory ~DRAM! capacitors was investigated. Prior to Ru electroplating on a TiN substrate, HF cleaning and Pd activation were performed. Removal of Ti oxide from the TiN substrate by HF treatment enabled Pd activation, which enhanced the nucleation of Ru on TiN substrate. Optimized pretreatments led to a continuous Ru film deposition. The surface roughness was measured to be 4.4 nm at 45 nm Ru film on the bare substrate. Moreover Ru electroplating method was also applied to a capacitor node-type TiN wafer. The deposition rate of Ru on the patterned wafer was the same as that on a bare wafer. The film showed 93% step coverage and good adhesion, comparable to CVD Ru films

The Inhibition of Silver Agglomeration by Gold Activation in Silver Electroless Plating

In Ag electroless plating, Ag agglomeration has been the obstacle to obtain thin Ag films. The crystallographic misfit between the substrate and Ag can accelerate Ag agglomeration. In this paper, Au, whose crystallographic characteristics are similar with those of Ag, is used as the activation material. As a result, the Ag layer was deposited in the form of layer-by-layer growth. Therefore, Ag film electrolessly deposited on a substrate activated by Au can be used to manufacture the interconnections in microelectronic devices. In this experiment, the resistivity of the Ag film was measured to 2.5 mV cm, which was decreased to 1.95 mV cm by the annealing process

Optimization of a Pretreatment for Copper Electroless Deposition on Ta Substrates

We investigated pretreatment methods for Cu electroless deposition on a Ta substrate. The native oxide on the substrate was effectively etched by the addition of HNO3 to a HF diluted solution and this was confirmed though X-ray photoelectron spectroscopy and chronopotentiometry. To form the Pd catalyst for Cu electroless deposition, a two-step Sn sensitization and Pd activation was carried out. The oxide removal enhanced the adsorption of the Sn ions on the Ta substrate and led to well distributed Pd clusters through Pd activation. By measuring the resistivity of the film, the Sn sensitization time and the Pd activation time were optimized through changes in the incubation time, at which the sheet resistance abruptly decreased by the film formation via the coalescence of Cu grains. The resistivity of the Cu electroless film deposited using the optimized pretreatment conditions was 3.59 cm, which was further reduced to 2.7 cm through an annealing process.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage RCECS , Dongbu Electronics, and by the Institute of Chemical Processes ICP

Percutaneous placement of self-expandable metallic stents in patients with obstructive jaundice secondary to metastatic gastric cancer after gastrectomy

OBJECTIVE: To evaluate the outcomes of patients undergoing percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy. MATERIALS AND METHODS: Fifty patients (mean age, 62.4 years; range, 27-86 years) who underwent percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy were included. The technical success rate, clinical success rate, complication rate, stent patency, patient survival and factors associated with stent patency were being evaluated. RESULTS: The median interval between the gastrectomy and stent placement was 23.1 months (range, 3.9-94.6 months). The 50 patients received a total of 65 stents without any major procedure-related complications. Technical success was achieved in all patients. The mean total serum bilirubin level, which had been 7.19 mg/dL ± 6.8 before stent insertion, decreased to 4.58 mg/dL ± 5.4 during the first week of follow-up (p < 0.001). Clinical success was achieved in 42 patients (84%). Percutaneous transhepatic biliary drainage catheters were removed from 45 patients (90%). Infectious complications were noted in two patients (4%), and stent malfunction occurred in seven patients (14%). The median stent patency was 233 ± 99 days, and the median patient survival was 179 ± 83 days. Total serum bilirubin level after stenting was an independent factor for stent patency (p = 0.009). CONCLUSION: Percutaneous transhepatic placement of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy is a technically feasible and clinically effective palliative procedure

Intramedullary Spinal Cord Metastasis of Choriocarcinoma

The authors describe a case of choriocarcinoma that metastasized to the cerebral cortex, vertebral body, and intramedullary spinal cord. A 21-year-old woman presented with sudden headache, vomiting and a visual field defect. Brain computed tomography and magnetic resonance examinations revealed an intracranial hemorrhage in the left temporo-parietal lobe and two enhancing nodules in the left temporal and right frontal lobe. After several days, the size of the hemorrhage increased, and a new hemorrhage was identified in the right frontal lobe. The hematoma and enhancing mass in the left temporo-parietal lobe were surgically removed. Choriocarcinoma was diagnosed after histological examination. At 6 days after the operation, her consciousness had worsened and she was in a state of stupor. The size of the hematoma in the right frontal lobe was enlarged. We performed an emergency operation to remove the hematoma and enhancing mass. Her mental status recovered slowly. Two months thereafter, she complained of paraplegia with sensory loss below the nipples. Whole spine magnetic resonance imaging revealed a well-enhancing mass in the thoracic intramedullary spinal cord and L2 vertebral body. Despite chemotherapy and radiotherapy, the patient died 13 months after the diagnosis

Transient receptor potential channel TRPV4 mediates TGF-β1-induced differentiation of human ventricular fibroblasts

Background: Cardiac fibroblasts (CFs) are principal extracellular matrix-producing cells. In response to injury, CFs transdifferentiate into myofibroblasts. Intracellular calcium (Ca2+) signaling, involved in fibroblast proliferation and differentiation, is activated in fibroblasts through transient receptor potential (TRP) channels, but the function of these channels has not been investigated in human ventricular CFs. Under evaluation in this study, was the role of TRP channels in the differentiation of human ventricular CFs induced by transforming the growth factor beta (TGF-β), a pro-fibrotic cytokine. Methods: Human ventricular CFs were used in this study. The differentiation of CFs into myofibroblast was induced with TGF-β and was identified by the expression of smooth muscle actin. Results: Results indicate that Ca2+ signaling was an essential component of ventricular CF dif­ferentiation. CFs treated with TGF-β demonstrated increased expression of a TRP channel, TRPV4, both at the mRNA and protein levels, which corresponded with CF-myofibroblast trans-differentiation, as evidenced by the upregulation of α-smooth muscle actin, a myofibroblast marker, and plasminogen activator inhibitor-1, which are fibrogenesis markers. An agonist of TRPV4 induced the conversion of CFs into myofibroblasts, whereas it’s antagonist as well a Ca2+ chelating agent reduced it, indicating that the Ca2+ influx throughTRPV4 is required for CF trans-differentiation. Overall, these results dem­onstrate that TRPV4-mediated Ca2+ influx participates in regulating the differentiation of human ventricular CFs into myofibroblasts through the MAPK/ERK pathway. Conclusions: Overall, these results demonstrate that TRPV4-mediated Ca2+ influx participates in regulating the differentiation of human ventricular CFs into myofibroblasts through the MAPK/ERK pathway

Anesthetic experience in patient for single lung transplantation with previous contralateral pneumonectomy -A case report-

A 48-year-old woman with cystic fibrosis and a previous left pneumonectomy had surgery planned for single lung transplantation under general anesthesia. Due to progressive dyspnea and recurrent respiratory infection, she could not maintain her normal daily life without lung transplantation. The anesthetic management and surgical procedure was expected to be difficult because of the left mediastinal shift and an asymmetric thorax after the left pneumonectomy, but the single lung transplantation was successfully done under cardiopulmonary bypass

Comparison of Alcian Blue, Trypan Blue, and Toluidine Blue for Visualization of the Primo Vascular System Floating in Lymph Ducts

The primo vascular system (PVS), floating in lymph ducts, was too transparent to be observed by using a stereomicroscope. It was only detectable with the aid of staining dyes, for instance, Alcian blue, which was injected into the lymph nodes. Some dyes were absorbed preferentially by the PVS than the lymph wall. It remains a standing problem to know what dyes are absorbed better by the PVS than the lymph walls. Such information would be useful to unravel the biochemical properties of the PVS that are badly in need for obtaining large amount of PVS specimens. In the current work we tried two other familiar dyes which were used in PVS research before. We found that Trypan blue and toluidine blue did not visualize the PVS. Trypan blue was cleared by the natural washing. Toluidine blue did not stain the PVS, but it did leave stained spots in the lymph wall and its surrounding tissues, and it leaked out of the lymph wall to stain surrounding connective tissues. These completely different behaviors of the three dyes were found for the first time in the current work and provide valuable information to elucidate the mechanism through which some special dyes stained the PVS preferentially compared to the lymphatic wall

The usefulness of contrast-enhanced ultrasonography in the early detection of hepatocellular carcinoma viability after transarterial chemoembolization: pilot study

Background/AimsThe therapeutic effect of transarterial chemoembolization (TACE) against hepatocellular carcinoma (HCC) is usually assessed using multidetector computed tomography (MDCT). However, dense lipiodol depositions can mask the enhancement of viable HCC tissue in MDCT. Contrast-enhanced ultrasonography (CEUS) could be effective in detecting small areas of viability and patency in vessels. We investigated whether arterial enhancement in CEUS after treatment with TACE can be used to detect HCC viability earlier than when using MDCT.MethodsTwelve patients received CEUS, MDCT, and gadoxetic-acid-enhanced dynamic magnetic resonance imaging (MRI) at baseline and 4 and 12 weeks after TACE. The definition of viable HCC was defined as MRI positivity after 4 or 12 weeks.ResultsEight of the 12 patients showed MRI positivity at 4 or 12 weeks. All patients with positive CEUS findings at 4 weeks (n=8) showed MRI positivity and residual viable HCC at 4 or 12 weeks. Five of the eight patients with positive CEUS findings at 4 weeks had negative results on the 4-week MDCT scan. Four (50%) of these eight patients did not have MRI positivity at 4 weeks and were ultimately confirmed as having residual HCC tissue at the 12-week MRI. Kappa statistics revealed near-perfect agreement between CEUS and MRI (κ=1.00) and substantial agreement between MDCT and MRI (κ=0.67).ConclusionsIn the assessment of the response to TACE, CEUS at 4 weeks showed excellent results for detecting residual viable HCC, which suggests that CEUS can be used as an early additive diagnosis tool when deciding early additional treatment with TACE