Influences of Plasma Treatment on the Electrical Characteristics of rf-magnefrom sputtered $BaTa_2O_6$ Thin Films

플라즈마 표면 처리가 $BaTa_2O_6$박막의 전기적 특성에 미치는 효과에 관한 연구

  • Published : 1999.05.01

Abstract

Direct current(d.c.)leakage current voltage characteristics of radio-frequencymagnetron sputtered BaTa\sub 2\O\sub 6\ film capacitors with aluminum(A1) top and indium tin oxide (ITO) bottom electrodes have been investigatedas a function of applied field and temperature. In order to study surfacetreatment effect on the electrical characteristics of as-deposited film weperformed exposure of oxygen plasma on $BaTa_2O_6$ surface. d. c.current-voltage (I-V), bipolar pulse charge-voltage (Q-V), d. c. current-time (I-t) andcapacitance-frequency (C-f) analysis were performed on films. All ofthe films exhibita low leakage current, a high breakdown field strength (3MV/cm-4.5MV/cm), and high dielectric constant (20-30). From the temperature dependence of leakage current,we can conclude that the dominant conduction mechanism is ascribed toSchottky emission at high electric field (>1MV/cm) and hopping conduction at lowelectric field (<1MV/cm). According to our results, the oxide plasma surfacetreatmenton as-deposited $BaTa_2O_6$ resulted in lowering interfacebarrier height and thus, leakage current when a negative voltage applied to the A1 electrode. This can be explained by reduction of surface contamination via etching surface and filling defects such as oxygen vacancies.

Keywords

$BaTa_2O_6$ thin films;ACTFELD;Oxygen Plasma treatment;High dielectric donstant

References

  1. J.Appl.Phys. v.82 Impact of surface properties on the dielectric breakdown for polycrystalline and multilayered BaTiO₃thin films J.H.Oh;Y.H.Lee;B.K.Ju;D.K.Shin;C.Y.Park;M.H.Oh
  2. J.Appl.Phys. v.81 Leakage currents in amorphous $Ta_2O_5$ thin films Fu-Chien Chiu(et al.)
  3. J.Appl.Phys. v.82 Leakage current in $Ba_{0.7}Sr_{0.3}TiO_3$ thin films for ultrahigh-density dynamic random access memories G.W.Dietz(et al.)
  4. Jpn. J.Appl.Phys. v.19 Effect of Heat Treatment on the Coefficient β pf for the Poole-Frenkel Effect and the Conductivity in $Ta_2O_5$ Films Hironaga Matsumoto
  5. ED v.44 Reduction of Leakage Current in Chemical-Vapor-Deposition $Ta_2O_5$ Thin Film by Furance N₂O Annealing S.C.Sun(et al.)
  6. J. Electrochem.Soc. v.144 Improvement of Adhesion Properties of Fluorinated Silica Glass Films by Nitrous Oxide Plasma Treatment Richard Swope(et al.)
  7. J. Electrochem. Soc. v.123 Chemical Vapor Deposition of Tantalum Pentaoxide Films for Metal-Insulator-Semiconductor Devices E.Kaplan(et al.)
  8. J. of Phys E v.9 A simple method for the determination of the optical constant n,k and the thickness of a weakly absorbing thin film C Manifacier(et al.)
  9. Thin Solid Films v.277 Dielectric constants of $Ta_2O_5$ thin films deposited by r.f. sputtering Susumu Shibata
  10. IEDM 93 Ultra-Thin TiN/$Ta_2O_5$/W Capacitor Technology for 1Gbit DRAM S.Kamiyama(et al.)
  11. J.Appl.Phys. v.59 Oxidation temperature dependence of the dc eletrical conduction characteristics and dielectrics and dielectric strenght of thin $Ta_2O_5$ films on silicon G.S. Oehrlein
  12. J. Crystal Growth v.167 Thickness effects of SiOxNy interlayer inserted between BaTiO₃insulating layer and ZnS:Mn phosphor layer in thin film electroluminescent device M.H.Song;Y.H.Lee(et al.)
  13. The Theory of Electrical Conduction and Breakdown in Solid Dielectrics J.J.ODwyer
  14. Appl.Phys.Lett. v.70 Surface modification of indium tin oxide by plasma treatment: An effective method to improve the efficiency, brightness, and reliability of organic light emitting devices C.C.Wu(et al.)