GeO2 based high k dielectric material synthesized by sol-gel process

Recently, there has been lot of research on new high dielectric constant (high k) materials for use in future generations of ultra-large scale integrated circuits (ULSI). There are number of requirements for the new high k materials, such as high dielectric constant, thermal stability (400 degrees C or higher), high mechanical strength, and good adhesion to neighboring layers. Keeping in view the properties required for the replacement of existing SiO2 dielectrics, new high k dielectric material based on GeO2 has been synthesized. Polycrystalline GeO2 thin films have been deposited by simple, and cost effective sol-gel spin coating process. The obtained xerogel films of germanium oxide have been annealed at 400 degrees C, 600 degrees C and 800 degrees C for 3 h in argon atmosphere. Elemental composition, morphology, and phase analysis have been measured by employing X-ray photoelectron spectroscopy, scanning electron microscopy, and X-ray diffraction techniques, respectively. The formation of the hexagonal GeO2 phase at and above 400 degrees C has been reported. The composition of the annealed films have been measured and found to be 68 at.% of O, 32 at.% of Ge for GeO2, which are close to the stoichiometry of the GeO2. (c) 2007 Elsevier B.V. All rights reserved.