Structural features and microwave properties of Ba0.5Sr 0.5TiO3 films grown on sapphire substrates

Kwang Hwan Cho, Jong Yoon Ha, Chong Yun Kang, Ji Won Choi, Young Pak Lee, Seok Jin Yoon

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The change in dielectric constant of ferroelectric materials as a function of electric field is the key to wide range of microwave application such as tunable filter, impedance matching network, and phase shifter, In this study, ferroelectric Ba0.5Sr0.5TiO3 (BST) films were grown on r-cut sapphire and polycrystalline sapphire (poly-sapphire) substrates by RF sputtering. The results of comprehensive structural diagnostics of the films are correlated with the dielectric constant and dielectric loss of a co-planar BST varactor, measured at a frequency range of 1-3 GHz. Textured BST films approximately 500 nm thick, grown on r-cut sapphire substrates, are characterized by high dielectric constant ≥ 650. However, polycrystalline BST films, grown on poly-sapphire substrates, are less strained, having dielectric constant range of 430-640.

Original languageEnglish
Title of host publicationDiffusion and Defect Data Pt.B: Solid State Phenomena
Pages1829-1832
Number of pages4
Volume124-126
EditionPART 2
Publication statusPublished - 2007 Dec 1
Externally publishedYes
EventIUMRS International Conference in Asia 2006, IUMRS-ICA 2006 - Jeju, Korea, Republic of
Duration: 2006 Sep 102006 Sep 14

Publication series

NameDiffusion and Defect Data Pt.B: Solid State Phenomena
NumberPART 2
Volume124-126
ISSN (Print)10120394

Other

OtherIUMRS International Conference in Asia 2006, IUMRS-ICA 2006
CountryKorea, Republic of
CityJeju
Period06/9/1006/9/14

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Keywords

  • BaSrTiO
  • Ferroelectric thin film
  • Tunable microwave device

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Cho, K. H., Ha, J. Y., Kang, C. Y., Choi, J. W., Lee, Y. P., & Yoon, S. J. (2007). Structural features and microwave properties of Ba0.5Sr 0.5TiO3 films grown on sapphire substrates. In Diffusion and Defect Data Pt.B: Solid State Phenomena (PART 2 ed., Vol. 124-126, pp. 1829-1832). (Diffusion and Defect Data Pt.B: Solid State Phenomena; Vol. 124-126, No. PART 2).