Cu-compatible ultra-high permittivity dielectrics for embedded passive components

Jon F. Ihlefeld, Angus I. Kingon, William Borland, Jon-Paul Maria

Research output: Contribution to journalConference article

7 Scopus citations

Abstract

Barium titanate thin films have been prepared by chemical solution deposition on 18 urn thick, industry standard copper foils in the absence of chemical barrier layers. The final embodiment exhibits randomly oriented BaTiO 3 grains with diameters between 0.1 and 0.2 μm, and an equiaxed morphology. The average film thickness is 0.6 μm and high resolution cross sectional microscopy shows no indication of interfacial phases. The BaTiO 3 films are sintered in a high temperature reductive atmosphere such that copper oxidation is avoided. Subsequent lower-temperature, higher oxygen pressure anneals are used to minimize oxygen point defects. Permittivities greater than 3000 are observed, with loss tangents under 2.5%. The BaTiO 3 phase exhibits pronounced ferroelectric switching and coercive field values near 20 kV/cm. Temperature dependent measurements indicate a ferroelectric transition near 100°C with very diffuse character. Combining the approaches of the multilayer capacitor industry with traditional solution processed thin films has allowed pure barium titanate to be integrated with copper, The high sintering temperature - as compared to typical film processing - provides for large grained films and properties consistent with well-prepared ceramics. Integrating BaTiO 3 films on copper foil represents an important step towards high capacitance density embedded passive components.

Original languageEnglish (US)
Pages (from-to)145-150
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
Volume783
StatePublished - Dec 1 2003
EventMaterials, Integration and Packaging Issues for High - Frequency Devices - Boston, MA, United States
Duration: Dec 1 2003Dec 3 2003

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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