Conduction mechanisms in barium tantalates films and modification of interfacial barrier height

Yun-Hi Lee, Young Sik Kim, Dong Ho Kim, Byeong Kwon Ju, Myung Hwan Oh

Research output: Contribution to journalArticle

Abstract

The leakage currentvoltage characteristics of rfmagnetron sputtered BaTa2Og film in a capacitor with the top aluminum and the bottom indiumtinoxide electrodes have been investigated as a function of applied field and temperature. In order to study the effect of the surface treatment on the electrical characteristics of asdeposited film we performed an oxygen plasma treatment on BaTa2Og surface. The dc currentvoltage bipolar pulse chargevoltage dc currenttime and small ac signal capacitancefrequency characteristics were measured to study the electrical and the dielectric properties of BaTa2Og thin film. All of the BaTa2Og films in this study exhibited a low leakage current a high breakdown field strength (34.5 MV/cm) and a high dielectric constant (2030). From the temperature dependence of the leakage current we could conclude that the dominant conduction mechanism under high electrical fields (>1 MV/cm) is ascribed to the Schottky emission while the ohmic conduction is dominant at low electrical fields (<1 MV/cm). Furthermore the oxygen plasma treatment on the surface of asdeposited BaTa2Og resulted in a lowering of the interface barrier height and thus a reduction of the leakage current at Al under a negative bias. This can be explained by the formation of Barich metallic layer by surface etching effect and by filling the oxygen vacancies in the bulk.

Original languageEnglish
JournalIEEE Transactions on Electron Devices
Volume47
Issue number1
Publication statusPublished - 2000 Dec 1
Externally publishedYes

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Keywords

  • Conduction mechanism
  • Dielectric thin films
  • Optoelectronic display
  • Sputtered films

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)

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