Determination of process margin and global planarization characteristics in the direct STI-CMP process

The direct shallow trench isolation–chemical mechanical polishing (STI–CMP) process without conventional reverse moat etch step was studied in order to compare the global planarization procedure in the each region with different pattern size. Because the removal rates of each region were different in the STI–CMP process, the determination of process margin is very important parameter in the viewpoint of exact control for polishing thickness. Therefore, the process margins (upper and lower limits), which can minimize the dishing effects in the large field area, were investigated through the analysis of global planarization. As a result, we could perfectly remove the silicon oxide on the silicon nitride layer in the moat region. This means that it was possible to achieve a global planarization without the complicated reverse moat process.     

A study on the correlation between electrochemical corrosion and chemical mechanical polishing performance of W and Ti film

In this paper, in order to investigate the electrochemical polishing behavior of the tungsten (W) and titanium (Ti) film, the chemical mechanical polishing (CMP) performances of W and Ti film according to the oxidizer contents were studied through electrochemical corrosion analysis. The alumina (Al₂O₃)-based tungsten slurry with H₂O₂ oxidizer was used for CMP test. As an experimental result, for the case of 5 vol% oxidizer added, the removal rates were improved and a good polishing selectivity of 1.4 : 1 was obtained. It means that the oxidizer with the highest removal rate (RR) has a high dissolution rate due to the predominant electrochemical corrosion effects. Therefore we conclude that the W and Ti-CMP characteristics are strongly dependent on the amounts of H₂O₂ oxidizer additive.     

Template directed formation of nanoparticle decorated multi-walled carbon nanotube bundles with uniform diameter

Bundles of multi-walled carbon nanotubes of uniform diameter decorated with Ni nanoparticles were synthesized using mesoporous silicates as templates. The ordered morphology and the narrow pore size distribution of mesoporous silicates provide an ideal platform to synthesize uniformly sized carbon nanotubes. In addition, homogeneous sub-10?nm pore sizes of the templates allow in?situ formation of catalytic nanoparticles with uniform diameters which end up decorating the carbon nanotubes. The resulting carbon nanotubes are multi-walled with a uniform diameter corresponding to the pore diameter of the template used during the synthesis that are decorated with the catalysts used to synthesize them. They have a narrow size distribution which can be used in many energy related fields of research.     

Enrichment of Phenolics in Harvested Strawberries by High-Pressure Treatment

In order to investigate the effect of a high-pressure (HP) treatment on enrichment of phenolics in harvested fresh strawberries, the total phenolic (TP) and anthocyanin (TA) contents were measured by colorimetry and the concentrations of ten individual phenolic compounds were analyzed by HPLC. While there were few changes in the physiochemical properties of strawberries, the contents of TP, (+)-catechin, p-hydroxybenzoic acid, and pelargonidin-3-O-glucoside were enriched at the 5% level of significance.     

Haplotype Analysis of BADH1 by Next-Generation Sequencing Reveals Association with Salt Tolerance in Rice during Domestication

Betaine aldehyde dehydrogenase 1 (BADH1), a paralog of the fragrance gene BADH2, is known to be associated with salt stress through the accumulation of synthesized glycine betaine (GB), which is involved in the response to abiotic stresses. Despite the unclear association between BADH1 and salt stress, we observed the responses of eight phenotypic characteristics (germination percentage (GP), germination energy (GE), germination index (GI), mean germination time (MGT), germination rate (GR), shoot length (SL), root length (RL), and total dry weight (TDW)) to salt stress during the germination stage of 475 rice accessions to investigate their association with BADH1 haplotypes. We found a total of 116 SNPs and 77 InDels in the whole BADH1 gene region, representing 39 haplotypes. Twenty-nine haplotypes representing 27 mutated alleles (two InDels and 25 SNPs) were highly (p < 0.05) associated with salt stress, including the five SNPs that have been previously reported to be associated with salt tolerance. We observed three predominant haplotypes associated with salt tolerance, Hap_2, Hap_18, and Hap_23, which were Indica specific, indicating a comparatively high number of rice accessions among the associated haplotypes. Eight plant parameters (phenotypes) also showed clear responses to salt stress, and except for MGT (mean germination time), all were positively correlated with each other. Different signatures of domestication for BADH1 were detected in cultivated rice by identifying the highest and lowest Tajima’s D values of two major cultivated ecotypes (Temperate Japonica and Indica). Our findings on these significant associations and BADH1 evolution to plant traits can be useful for future research development related to its gene expression.     

Thermally cross-linkable host materials for enabling solution-processed multilayer stacks in organic light-emitting devices

A thermally cross-linkable host material, i.e., two vinylbenzyl ether groups containing a carbazole derivative (DV-CBP), was developed for solution-processed multilayer organic light-emitting devices (OLEDs). DV-CBP was thermally cross-linked at styrene end-groups through curing at approximately 180 °C in the absence of a polymerization initiator. This cross-linking reaction rendered the emissive layer insoluble and enabled the subsequent solution deposition of an upper electron-transporting layer. Furthermore, photoluminescence quantum efficiencies of the emissive layer were maintained at greater than 75% throughout the cross-linking reaction. A solution-processed small-molecule electron-transporting layer on top of the cross-linked emissive layer led to lower driving voltages and higher efficiencies in the OLEDs compared to those of a device with a vacuum-deposited Ca electrode on the emissive layer.     

Preparation of size-controlled fine Al particles for application to rear electrode of Si solar cells

Micron-sized aluminum (Al) particles are widely used in the fabrication of rear electrodes of Si solar cells. Moreover, the rear electrode of Si solar cells can be fabricated at relatively low electrode firing temperature using submicron Al particles whose sizes can be easily controlled, but there have not been any clear methods to obtain submicron Al particles yet. In this study, we first successfully prepared size-controlled Al submicron particles via a wet chemical process using dibutyl ether solvent and then to fabricate rear electrodes of Si solar cells; to our knowledge, this is the first such application of submicron Al particles. The geometric mean diameter (D_p) of the Al particles could be controlled from 139 to 614 nm by adjusting the reaction temperature, and the prepared Al particles showed geometric standard deviations (σ_g) of 1.25-1.30. The Al particle size was reduced to ∼35 nm by adding an organic surfactant to the precursor solution for Al particle preparation. Rear electrodes were fabricated by firing the screen printed Al paste films comprising Al particles with geometric mean diameters of ∼379 nm from 600 to 900° C. The electrode fired at 750 °C showed the minimum electrical sheet resistivity of 77.9 mΩ/□ (specific resistivity: 97.3 μΩ cm) and contained a BSF (back surface field) with a thickness of ∼3 μm. Our results indicate that the reported method can be used to minimize the thermal defects in the rear electrode of Si solar cells by lowering the electrode firing temperature.     

递推混合最小二乘在红外焦平面阵列非均匀校正中的应用

基于递推最小二乘(RLS)的红外焦平面阵列非均匀校正算法具有计算量和存储量小等优点,易于工程实现.但RLS并不完全满足实际问题模型的要求,因此拟合出的噪声参数存在严重偏差.提出了一种利用递推混合最小二乘(RMLS)替代RLS进行非均匀校正的算法,它不但具有原方法的各种优点,而且由于符合问题模型的基本特征,因此在拟合精度和收敛速度方面都优于RLS.文中实验结果也验证了该方法的有效性.