Boni O, Berger S
Faculty of Materials Engineering, Technion, Haifa 32000, Israel.
J Nanosci Nanotechnol. 2001 Dec;1(4):433-9. doi: 10.1166/jnn.2001.061.
A new concept of a composite dielectric thin film fabrication is presented. The fabrication process consists of two stages. The first stage is anodizing a thin aluminum film to produce a porous alumina film that contains an array of nanometer sized parallel pores. The second stage is filling the pores with a saturated KDP (KH2PO4) liquid solution due to capillary forces. After drying KDP nanocrystals are formed inside the pores. This process results in a formation of a composite dielectric thin film composed of the alumina pores walls as one dielectric material and the KDP nanocrystals inside the pores as another dielectric material. The dielectric permittivity of this composite film is higher than that of the porous alumina film at all applied frequencies. The dielectric enhancement is more pronounced at low frequencies due to an interface polarization mechanism. This fabrication process enables controlling the size, composition, and microstructure of the composite dielectric film constituents and thus changing its dielectric properties over a wide range of values.
提出了一种复合介电薄膜制备的新概念。制备过程包括两个阶段。第一阶段是对薄铝膜进行阳极氧化，以制备出含有纳米尺寸平行孔阵列的多孔氧化铝膜。第二阶段是由于毛细作用力，用饱和KDP（KH2PO4）液体溶液填充这些孔。干燥后，孔内形成KDP纳米晶体。这一过程导致形成一种复合介电薄膜，其由氧化铝孔壁作为一种介电材料，孔内的KDP纳米晶体作为另一种介电材料组成。在所有施加频率下，这种复合膜的介电常数都高于多孔氧化铝膜。由于界面极化机制，在低频下介电增强更为明显。这种制备工艺能够控制复合介电膜成分的尺寸、组成和微观结构，从而在很宽的值范围内改变其介电性能。
