Effect of Ag doping on the performance of ZnO thin film transistor

Deuk Hee Lee, Ki Ho Park, Sangsig Kim, Sang Yeol Lee

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Ag-doped zinc oxide (SZO) thin film transistors (TFTs) have been fabricated using a back-gate structure on thermally oxidized and heavily doped p-Si (100) substrate. The SZO thin films were deposited via pulsed laser deposition (PLD) from a 1, 3, and 5 wt.% Ag-doped ZnO (1SZO, 3SZO, and 5SZO, respectively) target using a KrF excimer laser (λ, 248 nm) at oxygen pressure of 350 mTorr. The deposition carried out at both room-temperature (RT) and 200 °C. The SZO thin films had polycrystalline phase with preferred growth direction of (002) as well as a wurtzite hexagonal structure. Compare with ZnO thin films, the SZO thin films were characterized by confirming the shift of (002) peak to investigate the substitution of Ag dopants for Zn sites. The as-grown SZO TFTs deposited at RT and 200 °C showed insulator characteristics. However the SZO TFTs annealed at 500 °C showed good n-type TFT performance because Ag was diffused from Zn lattice site and bound themselves at the high temperature, and it caused generation of electron carriers. The post-annealed 5SZO TFT deposited at 500 °C exhibited a threshold voltage (Vth) of 11.5 V, a subthreshold swing (SS) of 2.59 V/decade, an acceptable mobility (μSAT) of 0.874 cm2/V s, and on-to-off current ratios (Ion/off) of 1.44 × 108.

Original languageEnglish
Pages (from-to)1160-1164
Number of pages5
JournalThin Solid Films
Volume520
Issue number3
DOIs
Publication statusPublished - 2011 Nov 30

Keywords

  • Ag-doped ZnO
  • Pulsed laser deposition
  • Thin film transistors
  • Zinc oxide

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Effect of Ag doping on the performance of ZnO thin film transistor'. Together they form a unique fingerprint.

  • Cite this