• 대한화학회지
• /
• 제60권2호
• /
• pp.111-117
• /
• 2016

본 연구에서는 이성분 격자 용액에서 용매-용질, 용질-용질 분자 사이에 특정상호작용이 존재하는 경우에 대한 새로운 혼합자유에너지식을 유도하였다. 특정상호작용이 일어날 확률은 이항분포를 만족한다고 가정하였다. 이 혼합자유에너지식을 이용하여 나타낼 수 있는 부분혼합도에 대한 유형을 조사하였고 Ω-모양의 온도-조성 상도가 존재할 수 있음을 보여 주었다. 그리고 물-2-부탄올에 대한 Ω-모양의 온도-조성 상도를 계산하여 Hino등 ⁵의 방법에 의한 계산값, 실험값과 비교하여 보았다.

• Transactions on Electrical and Electronic Materials
• /
• 제15권6호
• /
• pp.305-308
• /
• 2014

Organosilyl-modified and star-shaped poly (${\varepsilon}$-caprolactone) (m-PCL) was prepared, and added to polymethylsilsesquioxane (PMSSQ), to make composites. The end groups of m-PCL are chemically similar to PMSSQ, and m-PCL mixed well with PMSSQ in the composite. Porous PMSSQ film was made by further calcination of the composite film at elevated temperature. m-PCL-templated PMSSQ and the as-prepared porous PMSSQ were structurally, optically, and thermally characterized in thin films. The chemical binding of m-PCL and PMSSQ effectively suppressed the phase separation of PMSSQ and m-PCL during the curing process. After calcination at elevated temperature, there remained many pores in the PMSSQ matrix. The refractive indices of the resulting porous PMSSQ thin films decreased with increase of the film porosities, depending on the initial m-PCL loadings.

• 한국결정학회:학술대회논문집
• /
• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
• /
• pp.48-48
• /
• 2002

It is generally accepted that ultra low dielectric interlayer dielectric materials (k < 2.2) will be necessary for ULSI advanced microelectronic devices after 2003, according to the International Technology Roadmap for Semiconductors (ITRS) 2000. A continuous reduction of dielectric constant is believed to be possible only by incorporating nanopores filled with air (k = 1.0) into electrically insulating matrices such as poly(methyl silsesquioxane) (PMSSQ). The nanopo.ous low dielectric films should have excellent material properties to survive severe mechanical stress conditions imposed during the advanced semiconductor processes such as chemical mechanical planarization process and multilayer fabrication. When air is incorporated into the films for lowering k, their mechanical strength has inevitably to be sacrificed. To minimize this effect, the nanopores are controlled to exist in the film as closed cells. The micromechanical properties of the nanoporous thin films are considered more seriously than ever, particularly for ultra low dielectric applications. In this study, three approaches were made to design and develop nanoporous low dielectric films with improved micromechanical properties: 1) wall density increase of nanoporous organosilicate film by copolymerization of carbon bridged comonomers; 2) incorporation of sacrificial phases with good miscibility; 3) selective surface modification by plasma treatment. Nanoporous low-k films were prepared with copolymerized PMSSQ and star-shaped sacrificial organic molecules, both of which were synthesized to control molecular weight and functionality. The nanoporous structures of the films were observed using field emission scanning electron microscopy, cross-sectional transmission electron microscopy, atomic force microscopy, and positronium annihilation lifetime spectroscopy(PALS). Micromechanical characterization was performed using a nanoindentor to measure hardness and modulus of the films.