Fe-based pigments have attracted much interest owing to their eco-friendliness. In particular, the color of nanosized pigments can be tuned by controlling their size and morphology. This study reports on the effect of length on the coloration of β-FeOOH pigments prepared using an NH4OH solution. First, rod-type β-FeOOH is prepared by the hydrolysis of FeCl3·6H2O and NH4OH. When the amount of NH4OH is increased, the length of the rods decreases. Thus, the length of the nanorods can be adjusted from 10 nm to 300 nm. The color of β-FeOOH changes from orangered to yellow depending on the length of β-FeOOH. The color and phase structure of β-FeOOH is characterized by UVvis spectroscopy, CIE Lab color parameter measurements, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD).

We investigated cleaning effects using NH4OH solution on the surface of Cu film. A 20 nm Cu film was deposited on Ti / p-Si (100) by sputter deposition and was exposed to air for growth of the native Cu oxide. In order to remove the Cu native oxide, an NH4OH cleaning process with and without TS-40A pre-treatment was carried out. After the NH4OH cleaning without TS-40A pretreatment, the sheet resistance Rs of the Cu film and the surface morphology changed slightly(δRs:~10mΩ/sq.). On the other hand, after NH4OH cleaning with TS-40A pretreatment, the Rs of the Cu film changed abruptly (δRs:till~700mΩ/sq.); in addition, cracks showed on the surface of the Cu film. According to XPS results, Si ingredient was detected on the surface of all Cu films pretreated with TS-40A. This Si ingredient(a kind of silicate) may result from the TS-40A solution, because sodium metasilicate is included in TS-40A as an alkaline degreasing agent. Finally, we found that the NH4OH cleaning process without pretreatment using an alkaline cleanser containing a silicate ingredient is more useful at removing Cu oxides on Cu film. In addition, we found that in the NH4OH cleaning process, an alkaline cleanser like Metex TS-40A, containing sodium metasilicate, can cause cracks on the surface of Cu film.

Magnesium hydroxide sulfate hydrate whiskers (, abbreviated 513 MHSH) were prepared using hydrothermal reaction with magnesium oxide (MgO) and magnesium sulfate () as the starting materials. The effects of the molar ratio of /MgO and amount of were studied. As a result, 513 MHSH whiskers co-existed with hexagonal plate at low concentration of . The molar ratio of /MgO was 7:1, uniform 513 MHSH whiskers were formed without impurity such as . Appropriate amount of has affected to formation of high quality MHSH. Their morphologies and structures were determined by powder X-ray diffraction (XRD) scanning electron microscopy (SEM) and thermo-gravimetric analyzer (TGA).

본 연구에서는 NH(sub)4OH에 계면 활성제를 첨가한 세정액의 특성 및 세정 효과를 H(sub)2O(sub)2가 첨가된 NH(sub)4OH 세정액과 비교 연구하였다. NH(sub)4OH에 계면 활성제를 첨가한 경우 용액의 pH 및 산화 환원전위(Eh) 는 NH(sub)4OH의 값과 거의 유사하고 H(sub)2O(sub)2를 첨가한 경우에 pH는 감소하고 Eh는 증가하는 경향을 보였다. 표면장력은 계면 활성제를 첨가한 경우 약 72 dynes/cm에서 약 38dynes/cm로 감소하였으나 H(sub)2O(sub)2를 첨가한 경우에는 NH?OH 용액과 비교 거의 변화가 없었다. 실리콘 웨이퍼의 식각 속도를 측정한 결과 H(sub)2O(sub)2나 계면 활성제를 첨가하지 않은 초순수와 1 : 5(NH(sub)4OH : H(sub)2O(sub)2)의 부피비의 NH(sub)4OH용액이 첨가한 용액에 비해 최소 50배 이상의 높은 식각 속도를 보였다. 파티클 제거 실험에서 H(sub)2O(sub)2가 첨가된 NH(sub)4OH 세정액은 실험에 사용한 실리콘 표면위의 직경 0.67μm의 PSL파티클을 세정액의 온도와 무관하게 잘 제거하였으나 계면 활성제를 첨가한 NH?OH경우에 상온에서는 파티클을 제거할 수 없었으나 온도를 50˚C와 80˚C로 증가시킨 경우 H(sub)2O(sub)2가 첨가된 NH(sub)4OH와 유사한 세정 효과를 나타내었다.