Electrical properties of vanadium oxide thin films for bolometer applications: processed by pulse dc sputtering

Vanadium oxide (VOx) thin films were deposited on thermally grown silicon oxide substrates using a pure vanadium target in a pulsed dc sputtering technique. Film microstructure, electrical resistivity, temperature coefficient of resistance (TCR) and activation energy were studied as a function of the oxygen partial pressure (pO2) and growth temperatures. The mixed valence VOx thin films deposited at various substrate temperatures between 40 and 300 °C exhibited columnar grain structure even though the samples were found to be x-ray amorphous. The TCR and activation energies of the films increased from 0.4% (K−1) to 2.4% (K−1) and 0.04 eV to 0.28 eV, respectively, by controlling the pO2 content between depositions. The charge carrier transport in the VOx thin films was found to exhibit conventional and inverse Meyer–Neldel compensation mechanisms depending on the growth conditions.

[1]  R. Brook,et al.  The relationship between measured activation enthalpy and pre-exponential factor: Rate processes in ionic crystals in the intrinsic-extrinsic region , 1983 .

[2]  M. Ieda,et al.  The compensation law in electric conduction and dielectric relaxation for polyvinyl chloride , 1988 .

[3]  P. Fiorini,et al.  Characterization of bolometers based on polycrystalline silicon germanium alloys , 1998, IEEE Electron Device Letters.

[4]  C. H. Griffiths,et al.  Influence of stoichiometry on the metal‐semiconductor transition in vanadium dioxide , 1974 .

[5]  S. A. Shivashankar,et al.  Microstructure and properties of VO2 thin films deposited by MOCVD from vanadyl acetylacetonate , 2002 .

[6]  J. Meier,et al.  Electrical properties and degradation kinetics of compensated hydrogenated microcrystalline silicon deposited by very high‐frequency‐glow discharge , 1995 .

[7]  D. H. Hensler,et al.  Structural and Electrical Properties of Vanadium Dioxide Thin Films , 1968 .

[8]  X. Yi,et al.  Preparation of homogeneous VOX thin films by ion beam sputtering and annealing process , 2004 .

[9]  S. Baliga,et al.  Sputter deposition and characterization of Ni-Mn-O and Ni-Co-Mn-O spinels on polymide and glass substrates , 1990 .

[10]  C. T. Chen,et al.  Growth and properties of strained VOx thin films with controlled stoichiometry , 2003, cond-mat/0301263.

[11]  W. Spear,et al.  A new approach to the interpretation of transport results in a-Si , 1980 .

[12]  Daniel F. Murphy,et al.  320 x 240 silicon microbolometer uncooled IR FPAs with on-chip offset correction , 1996, Defense + Commercial Sensing.

[13]  N. Mott.  Introductory talk; Conduction in non-crystalline materials , 1972 .

[14]  Boris I Shklovskii,et al.  Coulomb gap and low temperature conductivity of disordered systems , 1975 .

[15]  K. Kosuge.  The phase diagram and phase transition of the V2O3−V2O5, system , 1967 .

[16]  R. Schropp,et al.  The inverse Meyer-Neldel rule in thin-film transistors with intrinsic heterogeneous silicon , 1999 .

[17]  M. D. Banus,et al.  ELECTRICAL AND MAGNETIC PROPERTIES OF TiO AND VO. , 1972 .

[18]  B. Batlogg,et al.  Normal and Inverse Meyer‐Neldel Rule in Nanocrystalline Pentacene Field‐Effect Transistors , 2000 .

[19]  I. Katardjiev,et al.  Frequency response in pulsed DC reactive sputtering processes , 2000 .

[20]  Vishal Mehta,et al.  Silicon-integrated uncooled infrared detectors: Perspectives on thin films and microstructures , 2005 .

[21]  J. L. Tissot.  IR detection with uncooled sensors , 2004 .

[22]  G. Lucovsky,et al.  An application of the statistical shift model to the inverted Meyer-Neldel, MN, relationship in heavily-doped microcrystalline Si, μc-Si , 1993 .

[23]  C. Julien,et al.  On the growth mechanism of pulsed-laser deposited vanadium oxide thin films , 2004 .