Doctoral Dissertations

James N. Reck

Abstract

Dielectric thin films of either TiO₂ or BaTiO₃ were sputtered in O₂/Ar plasmas on Si wafers to thicknesses ranging from approximately 25 to 200 nm with patterned Ni or Pt electrodes sputtered in Ar plasmas at thicknesses from about 20 to 250 nm to form nano-capacitors. Statistical design of experiments (DOE) was used to determine the effects of the deposition power, plasma composition, and deposition temperature on the measured electrical properties of the nano-capacitors. Additional tests to determine the effects of the dielectric and electrode thickness on the measured dielectric responses of the devices were also undertaken. Characterization was performed with a combination of direct current (DC) and alternating current (AC) testing methods including AC impedance, coercive field and leakage current versus voltage, scanning electron microscopy, transmission electron microscopy (TEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy, focused ion beam microscopy, and atomic force microscopy. The dielectric properties were found to depend on complex interactions of the process variables that could be modeled using statistical software. The permittivity was found to range from 100 to 10,000 with losses between 0.013 and 0.570. The resistance at 1 V DC varied from approximately 1.5 to 360 GΩ, and either a ferroelectric or paraelectric hysteretic response was observed for all specimens tested. Chemical analyses showed the films to be oxygen rich, while XRD and TEM data indicated the BaTiO₃ was amorphous. The electrical, chemical, and microstructural properties were found to depend on the sputtering conditions of the BaTiO₃, dielectric thickness, electrode material choice, and the electrode thickness. Collectively, the results indicated that the properties of nanometer thick dielectric and electrode materials have a significant impact on the measured electrical properties

Advisor(s)

OKeefe, Matt

Committee Member(s)

Kim, Chang-Soo
Miller, F. Scott, 1956-
Huebner, Wayne
Dogan, Fatih

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering

Sponsor(s)

Center for Dielectric Studies

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2008

Journal article titles appearing in thesis/dissertation

  • Electrical and statistical characterization of reactively sputtered TiOx capacitors with nickel electrodes
  • Analysis of RF-sputtered BaTiO₃ thin film capacitors with Ni electrodes using a statical design of experiments Part 1 - AC analysis
  • Analysis of RF-sputtered BaTiO₃ thin film capacitors with Ni electrodes using a statical design of experiments Part 2 - DC analysis
  • Thickness effects on the AC and DC electrical behavior of RF-sputtered BaTiO₃ nano-capacitors with Pt or Ni electrodes
  • Effects of Ni electrode thickness on the dielectric properties of nano-scale, RF-sputtered BaTiO₃ capacitors
  • Chemical and microstructural characterization of RF-sputtered BaTiO₃ nano-capacitors with Ni electrodes

Pagination

xiv, 220 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2008 James Nicholas Reck, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

CapacitorsDielectricsElectrodesNanotechnologySputtering (Physics)Thin films

Thesis Number

T 9461

Print OCLC #

354854318

Electronic OCLC #

316229969

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