DEVELOPMENT OF HIGH DIELECTRIC CONSTANT MATERIALS FOR MEMORY APPLICATIONS

Abstract

Neodymium doped polycrystalline samples of PNdZT, Pbi-3x/2 Nd x (Zr.65Ti.35) 03 wh x=.01,.03,.05,.07,.1 were prepared using conventional solid reaction route technique Studies the Nd+3 doped PZT reveal that donor doping at A-site. X-ray diffraction of these compoui show that they can be formed in single phase at 1050°C.Pellets prepared from the abc powders were sintered at 1150°C.Detailed studies of the Dielectric constant(K) and loss tang of the compounds at different frequencies at room temperature and temperature(RT to criti temperature 350°C ) suggest that the compounds undergo ferroelectric phase transition. 7 dielectric constant (K) is found to increase initially and then to decrease with increasing concentration. Motivation PNdZT with high dielectric constant can be used as a capacitor for high speed devices High materials are required for ULSI circuits, especially for DRAM (dynamic random acc memory).The storage capacitance in a DRAM has to maintain a certain value of capacitance proper operation .For a given capacitance, usually a minimum`d' is required to meet conditions of the maximum allowed leakage current and the minimum required break do-voltage. For a planar structure area `A' is reduced with increasing DRAM density. Therefc the dielectric constant of the material must be increased. Several high K-materials have bE prepared, including titanates such as BST (Barium strontium titanate) and PZT (Lead Zirconii Titanate). In the present work, we have synthesized Nd doped PZT ceramics with a general formula Pbi-3il2 Nd x (Zr.65Ti.35) 03 (X=.01,.03,.05,.07,.1) using the solid state reaction route The eff of the Neodymium doping on the structural and electrical properties of the samples have bE studied.