Search

Amorphous LaAlO3 films were deposited on hydrogen-terminated silicon substrates by atomic layer deposition (ALD) at 300 oC. The precursors were lanthanum tris(N,N'-diisopropylformamidinate), trimethylaluminum (TMA) and water. Capacitance-voltage measurements made on ALD MoN/LaAlO3/Si stacks showed humps especially at low frequencies. They were effectively removed by O2 treatment at 300 o C without affecting the dielectric constant (kappa~15). The O2 treatment can be carried out either after deposition of a LaAlO3 film, or after each ALD cycle. The O2 treatment also lowered the leakage current from 80 mA cm-2 to 1 mA cm-2 for EOT = 1.3 nm. This indicates that oxygen vacancies are the main defects in as-deposited LaAlO3. Oxygen treated LaAlO3 is one of the best candidates for future high-kappa dielectric material due to its low leakage, low defect density and abrupt interface with silicon., Chemistry and Chemical Biology

The effect of H2O and O3 oxidants on the behavior of residual C and N-related impurities as well as Si out-diffusion and interfacial layer formation in atomic-layer-deposited La2O3 films grown at 250 °C were examined using in situ x-ray photoelectron spectroscopy. The silicate formation was suppressed in a La2O3 film grown using O3 compared to that deposited using H2O, but interfacial layer growth was enhanced. The accumulation of C and N-related residues with low binding energy, which originated from incomplete reactions, was suppressed in La2O3 films grown using O3. However, the use of O3 resulted in La-carbonate phase in film. [ABSTRACT FROM AUTHOR]

Purpose: To explore the correlation of expression of long non-coding RNA (lncRNA) zinc finger E-box binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in gastric cancer tissues, analyze the correlations of its expression level with the clinicopathological features of gastric cancer and the malignant phenotype of tumor cells, and investigate the molecular mechanism of action of ZEB2-AS1 in gastric cancer., Methods: The expression level of ZEB2-AS1 in gastric cancer tissues and cancer-adjacent tissues in 56 patients was detected by fluorescence real-time quantitative polymerase chain reaction (qRT-PCR). AGS human gastric cancer cells were transiently transfected with small interfering lncRNA (si-lncRNA) ZEB2-AS1 using RNA interference technique, and its effect on proliferation of gastric cancer cells was assessed via MTT assay. Hoechst 33342 staining and flow cytometry were performed to examine the effect of ZEB2-AS1 on the apoptosis of AGS cells and scratch and Transwell assay were applied to detect the effect of si-ZEB2-AS1 on the invasion and metastasis of AGS cells., Results: qRT-PCR results showed that the expression of ZEB2-AS1 in cancer tissues was increased compared with cancer-adjacent tissues. Cell Counting Kit-8 (CCK-8) results indicated that knockdown of ZEB2-AS1 could significantly inhibit the proliferation of AGS cells. Hoechst 33342 staining and flow cytometry demonstrated that knockdown of ZEB2-AS1 obviously promoted the apoptosis of AGS cells. According to scratch and Transwell assay, knocking down ZEB2-AS1 could remarkably inhibit the invasion and metastasis of AGS cells. Western blotting results revealed that knocking down ZEB2-AS1 could inhibit cell invasion and metastasis by suppressing the epithelial to mesenchymal transition (EMT) as well as the expressions of matrix metallopeptidase-2 (MMP-2) and MMP-9 in AGS cells., Conclusions: The expression of lncRNA ZEB2-AS1 in gastric cancer tissues is significantly higher than in cancer-adjacent tissues. Patients with highly expressed lncRNA ZEB2-AS1 have a poor prognosis, and knockdown of lncRNA ZEB2-AS1 in AGS cells inhibits cell proliferation, invasion and metastasis, and promotes apoptosis.